If built to the same rpm goal with the correct parts to match each build, there won't be 10 hp difference between them. This was actually tested by one of the magazines a few years ago. 383 and 377 with the same parts.

My thoughts on destroking an engine are "Why take cubes away from an engine? Cubic inches = HP, making an engine smaller is just stoopid :drunk: .

Using modern engine components the 406 will rev just as high as the 377, and so will the 383.

I'n sure all the "revs faster" and "revs higher" fools will post up in this thread shortly.

 

If built to the same rpm goal with the correct parts to match each build, there won't be 10 hp difference between them. This was actually tested by one of the magazines a few years ago. 383 and 377 with the same parts.

My thoughts on destroking an engine are "Why take cubes away from an engine? Cubic inches = HP, making an engine smaller is just stoopid :drunk: .

Using modern engine components the 406 will rev just as high as the 377, and so will the 383.

I'n sure all the "revs faster" and "revs higher" fools will post up in this thread shortly.

now would the 406 be a stroked up or bored out 400? i didnt know u could stroke up a 400? I am looking to build a smallblock nat. asperated that will make 500hp and be able to rev to 8000rpm without it coming undone. which would be the best route on a 8k budget?

 

406 is just a 400 bore .030" oversize with the factory stock 3.75" stroke, you could also use a 3.875" "stroker" crank to make a 421 at the .030" overbore in a 400.
Either of these, and the 383 will easily be able to make 500+ hp and you won't need to rev them over 6800 rpm to do it. If done properly 8000 rpm is 700 hp territory for any of these engines, but is unnecessarily hard on parts, and you won't likely be able to do it on an $8,000 budget. The heads alone(BIG) to make power at 8000 rpm will cost $3500 all by themselves, then you have to add the valvetrain..

What is the reason you want to rev the snot out of it? If 8000 rpm and just 500hp and budget are your goals build a little bitty Z28 302 clone with a roller cam. It still won't keep up with a 6800 rpm 383 or 406.

Rpm just for the sake of rpm, or bragging rights, isn't very smart.

 

406 is just a 400 bore .030" oversize with the factory stock 3.75" stroke, you could also use a 3.875" "stroker" crank to make a 421 at the .030" overbore in a 400.
Either of these, and the 383 will easily be able to make 500+ hp and you won't need to rev them over 6800 rpm to do it. If done properly 8000 rpm is 700 hp territory for any of these engines, but is unnecessarily hard on parts, and you won't likely be able to do it on an $8,000 budget. The heads alone(BIG) to make power at 8000 rpm will cost $3500 all by themselves, then you have to add the valvetrain..

What is the reason you want to rev the snot out of it? If 8000 rpm and just 500hp and budget are your goals build a little bitty Z28 302 clone with a roller cam. It still won't keep up with a 6800 rpm 383 or 406.

Rpm just for the sake of rpm, or bragging rights, isn't very smart.

that is very true. i like the thought of a 383. but people have told me they are truck motors not car motors. iw ould also like to run a good radical sounding cam in it. i heard that the 377 is more of a reving engine but like u said its hard on parts. would it be best to get a short block and then add my own top end or buy a turn key?

 

377's as I think already stated are simply a destroked 406.... (3.48" stroke instead of the factory 3.75") The primary benefit is the improved rod to stroke ratio you can achieve, and thus in theory increase potential rpm safely. However, nowadays, it is clear you can run a 406 safely up to respectable rpm's of 7000 rpm and even a bit above depending on how built.

With a 377 vs 383, the battle is torque vs HP..... the 377 with the bigger bore will in theory will help unshroud the valves and thus free up a bit of HP, the 383 with its superior 3.75" stroke will build more off-idle torque...... In this case, for a street motor, I would chose the 383, for a track car, the 377 would probably be a bit quicker provided you have appropriately geared and stalled your motor. (In that test you mention, the 383 made approxmiately 10-15 more ftlbs of torque below 5000 rpm, the 377 made 10-15 more HP above 5000 rpm)

Having said the above, unless you are racing in a heads-up class requiring a cubic inch limit or you are road racing with extended periods of high rpm driving, there is no good reason to build a 377 in my opinion..... if you have a 4.125-4.155 bore block, throw in a minimum 3.75" stroke and have fun.... below 7000 rpm, you would probably make approxmiately 15-25 more torque and hp than a 377. If you have an aftermarket block, I recommend a 3.875" or 4.00" stroke. (For a 421 or 434)

With whatever you do, have fun and good luck !

 

The aftermarket block, rotating assembly, valvetrain, and heads will cost you more than 8G's for 8K RPM. That is IF you want to make power. If you just want to spin it and make noise then you can do that with a 350 on a 4bolt factory block, a lazy solid cam, and some decent 200cc heads with a budget forged long rod rotating assembly. Form what you posted it sounds like your more after noise than power so there the way to go. Factory 400 blocks can't take 8,000 RPM for too long.

 

We`ve ran them all. 350, 372, 383, and straight 400.
Hands down the 400 made them all look bad. We used it in a full size short wheel base chevrolet high sierra 4x4. We mud raced using 37 inch tall buckshot mudders. The 400 had stock rods, TRW forged 12cc dish pistons, 461 camel back heads that were bowl ported with stock valves. A weiand action plus intake, cyclone 1 5/8 headers, 850 Holley mech. secondary, a cheapy summit cam kit that had duration @.050 .234 In. .244 Ex.
A turbo 350 tranny, TCI 3500 Stall converter, 3.08 gears with front and rear posi traction. With the transfer case in 4 wheel low, Stall it at the line, when the light goes green nail it, it would break all 4 of the buckshots loose, that`s serious torque. We have many 1st place trophy`s to show for the effort.
On the drag strip we ran the same engines. The 372 which was a standard bore 400 block with a 350 crank performed very well. Our main nemesis was a fellow running a 383 in a monza, we ran a Nova. We never out ran him, but every race we lost to him was by a fender lenth. The next year we returned with the 400 with Dart II heads, the rest of the combo was the same as above and we installed it in a Vega. We cleaned his clock by about 2 car lenths. The 383 did okay until we took it to the mud races. The pit was more water than mud, the engine inhaled some water and 6 out of 8 compression rings broke in the process so we never got to see what it could do in it`s full potential.

 

Our 11-1 383 with Pro-Action(now RHS) Iron Lightning heads just went a new best for this engine of 10.61 @ 124 MPH at the Pinks All Out race today at US 131 Martin, Mi. 3400 lb '67 El Camino, Powerglide w/t-brake, 4200 stall. Motor is nothing real special, $3500 in parts and machining, Scat cast crank and rods, TRW forged flat tops. Spins to 7600 all the time, 7200 shift point. Been together 6 years, refreshed with new rings and bearings just once, it was last year.

We missed the cut by just .05 seconds , they took 10.3x- 10.56 second group of 32 cars. Event was a total blast. Coolest big event I've been to in a while.

Definately not a "truck motor", even though it is in a vehicle with a bed

 

Our 11-1 383 with Pro-Action(now RHS) Iron Lightning heads just went a new best for this engine of 10.61 @ 124 MPH at the Pinks All Out race today at US 131 Martin, Mi. 3400 lb '67 El Camino, Powerglide w/t-brake, 4200 stall. Motor is nothing real special, $3500 in parts and machining, Scat cast crank and rods, TRW forged flat tops. Spins to 7600 all the time, 7200 shift point. Been together 6 years, refreshed with new rings and bearings just once, it was last year.

We missed the cut by just .05 seconds , they took 10.3x- 10.56 second group of 32 cars. Event was a total blast. Coolest big event I've been to in a while.

Definately not a "truck motor", even though it is in a vehicle with a bed

pinks all out! I wish my car was ready for the one by my house this summer. I have an 85 elcamino i am gonna be putting this motor in. it sounds like the 383 is the way to go. i am looking at proformance unlimited for my builder. does their 383 mechanical roller 510 hp for 9k sound like a good way to go? it comes ready to drop in. could u check these guys out and see the build and let me know what you think? What do you think would be a good tranny rear gear set up for this? i want it to be a scary fast street car and a good performer on the strip. i really appreciate the advice. A MUSTANG KILLER! :mwink:

 

cubes are cubes. For many years people thought that stroke made torque and bore made HP, but that has been proven untrue a few million times. Throw the same parts at a Buick 455 (big bore, short stroke) and an Olds 455 (small bore, long stroke) and they will make the same power. Its true that longer strokes have more leverage on the crank, but with a smaller bore pushing on it, it is a wash.

Destroking is a quest for RPMs. In racing, it sometimes makes sense. On the street, it never makes sense. The only time destroking makes sense is if you're trying to spin more RPMs than your current rotating weight can handle. From idle to 5000 rpms, it doesn't really matter what the bore/stroke ratio is for most common V8s; they'll make the same power and torque.

So, I guess the question is, what are your goals? If you're building a street engine, destroking for fewer cubes is kinda counterproductive. You can make the same HP, but with less torque and you'll have to rev it higher to get your powerband. On the street, cubes are king. Don't destroke unless you're looking for 7000+ out of an SBC

Back to the buick/olds comparison: They will make the same torque and HP on the street. If you plan on going over 5500 RPMs, the small bore of the olds becomes a limitation to valve size and therefore flow. If you're looking for additional peak HP in higher RPM ranges, choose a bore/stroke combo that puts the emphasis on larger bore. In your case, you're talking about either destroking a 4.125" bore, or stroking a 4.030" bore. Both will perform great, but why destroke? Keep the 400 cubes and take advantage of the extra displacement.

 

cubes are cubes. For many years people thought that stroke made torque and bore made HP, but that has been proven untrue a few million times. Throw the same parts at a Buick 455 (big bore, short stroke) and an Olds 455 (small bore, long stroke) and they will make the same power. Its true that longer strokes have more leverage on the crank, but with a smaller bore pushing on it, it is a wash.

Destroking is a quest for RPMs. In racing, it sometimes makes sense. On the street, it never makes sense. The only time destroking makes sense is if you're trying to spin more RPMs than your current rotating weight can handle. From idle to 5000 rpms, it doesn't really matter what the bore/stroke ratio is for most common V8s; they'll make the same power and torque.

So, I guess the question is, what are your goals? If you're building a street engine, destroking for fewer cubes is kinda counterproductive. You can make the same HP, but with less torque and you'll have to rev it higher to get your powerband. On the street, cubes are king. Don't destroke unless you're looking for 7000+ out of an SBC

Back to the buick/olds comparison: They will make the same torque and HP on the street. If you plan on going over 5500 RPMs, the small bore of the olds becomes a limitation to valve size and therefore flow. If you're looking for additional peak HP in higher RPM ranges, choose a bore/stroke combo that puts the emphasis on larger bore. In your case, you're talking about either destroking a 4.125" bore, or stroking a 4.030" bore. Both will perform great, but why destroke? Keep the 400 cubes and take advantage of the extra displacement.

If you are running it on the street I suggest running a 5.7" rod- actaully a good stock rod with ARP bolts will be a great match. You get better rod angualarity and a lighter piston for very minimal cash- a good set of remaned rod will be about $125- the same as remanning your 400 rods. If you keep it under 6500 RPM and no detonation the rods will live fine- higher than that and you're probably going to blow the stock block.

Best bet for a cheap low trouble street combo- 400 with 5.7 rod. A 6" rod will lead to oiling issues- best left to the track.

 

$9000 spent and it only makes 510 hp??? WTH?? You should be easily able to make thar much power for less than half that much money. $9000 should result in a 700+ hp giant killer of a smallblock. Buying a complete motor from a crate is not really the most cost effective way to do it. Maybe look at Scott Shafiroff Racing engines. My cousin bought a Shafiroff 582 BBC (makes 968hp) for just a little over $11,000 dyno'ed and delivered, for his mud racer.

 

$9000 spent and it only makes 510 hp??? WTH?? You should be easily able to make thar much power for less than half that much money. $9000 should result in a 700+ hp giant killer of a smallblock. Buying a complete motor from a crate is not really the most cost effective way to do it. Maybe look at Scott Shafiroff Racing engines. My cousin bought a Shafiroff 582 BBC (makes 968hp) for just a little over $11,000 dyno'ed and delivered, for his mud racer.

ok. yeah that seems like a good idea.r they a pretty good builder? i thought it was a little much. plus they dont dyno the engines so you dont know if they are a true 500hp motor as they say. thanks for your help eric.

 

$9000 spent and it only makes 510 hp??? WTH?? You should be easily able to make thar much power for less than half that much money. $9000 should result in a 700+ hp giant killer of a smallblock. Buying a complete motor from a crate is not really the most cost effective way to do it. Maybe look at Scott Shafiroff Racing engines. My cousin bought a Shafiroff 582 BBC (makes 968hp) for just a little over $11,000 dyno'ed and delivered, for his mud racer.

I should clarify -- When I say you could do it for half that much, I mean you will have to build it yourself. Still, only 510 hp for $9000 isn't much of a deal. Shafiroff has a good reputation, builds Pro Stock engines for some of the NHRA/IHRA teams, and there are other good choices out there, shop around/search.

 

If you are running it on the street I suggest running a 5.7" rod- actaully a good stock rod with ARP bolts will be a great match. You get better rod angualarity and a lighter piston for very minimal cash- a good set of remaned rod will be about $125- the same as remanning your 400 rods. If you keep it under 6500 RPM and no detonation the rods will live fine- higher than that and you're probably going to blow the stock block.

Best bet for a cheap low trouble street combo- 400 with 5.7 rod. A 6" rod will lead to oiling issues- best left to the track.

Oiling Issues- just what do you think the oiling issues are.

 

AP's probably talking about the piston pin getting into the oil ring land when using 6" rods. Piston & ring design have come along way now and it's not that big a deal. I think some pistons for 6" rods don't intrude there now.

 

It is not as big of a deal now, but to some people burning 1-2 quarts of oil between changes it is still a big deal- I think it is, while many people think its fine. But when you expect to burn a quart of oil on a brand new engine between changes to me it sends up a red flag. In drag applications it may not be as big of a deal, and many people live with it in stroked ut LS engines, but I like my oil below the oil ring, not on top.

I know many will argue this and really I guess its a personal choice- I like the pin below the ring.

 

It is not as big of a deal now, but to some people burning 1-2 quarts of oil between changes it is still a big deal- I think it is, while many people think its fine. But when you expect to burn a quart of oil on a brand new engine between changes to me it sends up a red flag. In drag applications it may not be as big of a deal, and many people live with it in stroked ut LS engines, but I like my oil below the oil ring, not on top.

I know many will argue this and really I guess its a personal choice- I like the pin below the ring.

Appreciate your opinion/choice, I just have never experienced the oil problem- guess my #2 ring was always doing its job. I do believe that using 6" rod in a pure street application is a waste of time and money.

 

I should clarify -- When I say you could do it for half that much, I mean you will have to build it yourself. Still, only 510 hp for $9000 isn't much of a deal. Shafiroff has a good reputation, builds Pro Stock engines for some of the NHRA/IHRA teams, and there are other good choices out there, shop around/search.

I am now eye balling shafiroff's 427 sbc with the hhr kit.making 560hp for 8k. plus the quality of parts are top notch. what do you think about a 427 sbc? hydraulic or mechanical?? i thank you for all your input.

 

A pretty good piece for someone who can't build their own. If you want to be the Killer on your street I'd go mechanical as long as you feel you can do the maintainence on the valvetrain. Mechanical will kick hydraulic around any day of the week.

 

There is nothing "stoopid" about building a 377. for starters you can build one out of left over parts from a stroker build. Second, a 377 has less reciprocating mass/lower piston speeds and therefore it can obtain a bit more r's on a smaller budget. That is not opinionated hype, it is physics, you start revving a 400 up to 7000 plus rpms and youd better have some cash into that bottom end.

Then there is bore to stroke ratio, if you are building a rock crawler then by all means use as much stroke as possible. A circle track engine is a whole different story. Nothing "stoopid" about it, just a matter of what you want to acomplish..

 

There is nothing "stoopid" about building a 377. for starters you can build one out of left over parts from a stroker build. Second, a 377 has less reciprocating mass/lower piston speeds and therefore it can obtain a bit more r's on a smaller budget. That is not opinionated hype, it is physics, you start revving a 400 up to 7000 plus rpms and youd better have some cash into that bottom end.

Then there is bore to stroke ratio, if you are building a rock crawler then by all means use as much stroke as possible. A circle track engine is a whole different story. Nothing "stoopid" about it, just a matter of what you want to acomplish..

While the 377 can shine in circle track, it does not make the most sense for street, street/strip, or all out drag race. You are going to have to turn the 377 up over 8000rpm to really make it shine, and a 7500 rpm street or drag 406 bottom end is not that expensive. I've built both, I once bought into the "high rpm 377" hype, it wouldn't run with a less expensive 406, even though it was strong. This was drag and street use, I've never done the circle track thing, too rich for my blood.

 

427

in my reading of this thread I am not convinced you want to buy a piece that needs maintance, go hydrallic and have fun. if going to the strip you will more then likly be bracket racing and consistancy is wins there. can't go wrong with schiroff

 

While the 377 can shine in circle track, it does not make the most sense for street, street/strip, or all out drag race. You are going to have to turn the 377 up over 8000rpm to really make it shine, and a 7500 rpm street or drag 406 bottom end is not that expensive. I've built both, I once bought into the "high rpm 377" hype, it wouldn't run with a less expensive 406, even though it was strong. This was drag and street use, I've never done the circle track thing, too rich for my blood.

You are right that typicaly you will get more bang for your buck with more cubes, but horsepower is horsepower. There is a guy who has been racing a DZ 302 Z-28 on the drag strip (not circle track) since the late 60's and still does very well in the pure stock class. (Trying to remember his name) He held NHRA track records for I think it was two years. The basic trick is he uses a four speed and very low gears in the pumpkin, just runs in a higher range where the power for that motor lives. Again, not hype, just physics.

Strokers and 400's are more versatile and extremly effective for most applications, that it true. Still, a lot of guys are building up 350's for the street and I garantee a 377 will pull more torque than a 350, but you dont hear a lot of folks bagging on 350 users as being weak for the street/strip. Hype indeed.

There may not be a replacement for displacement, but a sound plan will always trump a bigger hammer.

 

You are right that typicaly you will get more bang for your buck with more cubes, but horsepower is horsepower. There is a guy who has been racing a DZ 302 Z-28 on the drag strip (not circle track) since the late 60's and still does very well in the pure stock class. (Trying to remember his name) He held NHRA track records for I think it was two years. The basic trick is he uses a four speed and very low gears in the pumpkin, just runs in a higher range where the power for that motor lives. Again, not hype, just physics.

Strokers and 400's are more versatile and extremly effective for most applications, that it true. Still, a lot of guys are building up 350's for the street and I garantee a 377 will pull more torque than a 350, but you dont hear a lot of folks bagging on 350 users as being weak for the street/strip. Hype indeed.

There may not be a replacement for displacement, but a sound plan will always trump a bigger hammer.

The fact that you bring a factory Stocker DZ 302 into the discussion tells me where your learning curve is. Put my $4500, Pump Gas, Solid Roller, 7400 rpm 406 in the same Camaro with gears friendly to the 406, and I'll smoke him heads up.

I bag on my friends that have them that their 350's are small. Leave it at 355 instead of 383 for any reason other then class cubic inch limits, then you made a poor choice.