400 HP on a 383 is a walk in the park, but, we need to know more about your parts.Which pistons are you using & their volume in cc's.You can't choose a cam, or, heads for that matter without that info, along with the piston to deck hgt @ TDC. You have to know what your actual compression ratio will be.
Another problem I see is the exhaust.Using stock manifolds is gonna choke most cams that would get you to your HP goals.

 

One of several things that you need to know in order to install the right cam in a motor is the static compression ratio. In order to figure the SCR, you need these values:
Bore
Stroke
Combustion chamber cc's
Head gasket bore and compressed thickness
Piston crown configuration and cc's of dome, eyebrows or dish
Distance from crown of the piston to the block decks where the heads bolt on, with the piston at top dead center.

Once you know the SCR, you will also need the following:
Will the vehicle be used for street or strip or a little of both?
What will be the weight of the vehicle?
What tire size?
What gear ratio in the rear end?
What transmission?
What rocker arm ratio?
What is the block deck height?
What intake manifold and what carburetor?
What type of cam, flat tappet hydraulic, flat tappet solid lifters, roller hydraulic or roller solid lifters?

If you will bless us with these values, we can figure the SCR and then suggest a cam for you.

If you will expand your budget on heads to just under $1200, you can buy arguably the best aluminum heads on the planet, the Profiler 23 degree heads, 195cc intake runners.
https://www.profilerperformance.com/176-sbc-23-degree-heads.html

 

Sorry, Stock manifolds are being released with some kind of headers. Here's the info on the stroker kit info.
https://m.summitracing.com/parts/esp-b13405e030

 

Stupid phone, thats replaced.

 

Do you plan on running the stock hood. this is an issue at those power levels not many combos that will clear the stock hood. Its really tight in there.

Definitely planning on keeping the stock hood.

 

With the pistons listed for your rotating assembly, the 64cc heads linked above is gonna put your compression ratio over 11:1.That's what happens when ppl are so anxious to "help"& don't take time to really look at the entire combo of parts you're using.While that compression would be workable with very careful cam selection, you would be better served by choosing a head that is available in a larger chamber, or, switching to a piston with more volume.The heads that Tech linked above, Profiler, are available in a 72cc chamber & are a much better head even tho slightly over your budget.They would make your HP goals alot easier & even with less cam needed with the other head to get the same results.

 

You can make 400 HP with 10:1 compression, so, why run over 11:1 just so you can use that head & again "make it work"? Why not just use the rite parts along with a safer easier to deal with compression & cam.Why run a bigger than needed cam & excessive compression just so you can use a cheap head.Why "make it work" when the correct parts will work better without having to make it work.There are other heads available with more volume that will work without being made to work.

 

Blueprint's head is an offshore casting, but it is a clean sheet effort designed by BluePrint's own people. While I haven't touched one personally, word around the engine forums is that it is a decent piece and no where near as poorly made as say ProComp.

Appears to be on the same level as ProMaxx, which is another import casting, finish machined and assembled here in the US. BluePrint does the same thing.

MTA, you may want to look at PROMaxx heads also, they have a 72cc chamber available, the 185cc intake runner would probably be right up your alley.

You may want to consider a Weiand Accelerator intake, I normally shy away from the Weiand Accelerator/Edelbrock Torker II because as short single plane intakes they don't work nearly as well as a good tall race single plane or even the Weiand Warrior/Edelbrock Performer RPM dual planes....but with the stock Corvette hood it is about all that will fit.

 

As you're finding out, it's always best to build a motor on paper & do all the math before you start actually buying parts.
For the type build you are looking at with an aluminum head, I would want to limit my compression to around 10.5:1.While 11.2:1 doesn't sound like a big jump, it is & there won't be a big performance gain from doing so.You gain more performance & power with the lower compression & the ability to tune the engine with a better timing curve than boosting compression. While raising compression on an 8.5:1 motor to over 9:1 can have a big impact, it is less effective in higher ranges.
If you were shooting for 500 HP, then it may be needed due to the cam you would be looking at, but, for 400 HP 383, it's just not needed, or, a very good idea.
IIRC, I don't think the Blueprint heads come in a larger chamber head.They may tho.The ProMaxx is a good alternative & will perform just as well as that NKB for the approx same $$ & not provide you with excessive compression.If you could possibly swing another $200 over your $1000 budget, the Profiler would be a much much better choice all the way around.Quality & performance.

 

For what it's worth Jegs advertites this kit as having the following Comp. Ratio 58cc/64cc/76cc: 11.4/10.7/9.4
Summit has it list as 10.38:1 on 64cc heads.
Guess I'll know more Wednesday when I have the actual parts in my hand.

 

Those compression ratios are based on & assuming a .025 piston to deck & using a .041/.039 headgasket,which will set your quench to the mid .060" range.This will make your motor more detonation prone than the higher compression provided with a .035" to .045" quench distance.


You will be better to lower the compression to 10.5:1,or,under & gain your performance with proper tuning & timing.There is a lot more to gained by being able to set up a good timing curve than raising compression & a lot less risk.Being able to add a few more degrees in timing will net you much better gains than a rise in compression.

 

After reading everyone's comments I'm now leaning towards these 68cc heads, thoughts?
Skip White Performance Detail Description

 

How about comparing intake flow numbers with the NKB's and the Pro-Filer heads. NKB .200-138, .300-188, .400-227, .500-244, .550-250. Pro-filers .200-145, .300-209, .400-254, .500-273, .600-274. Clearly you see the difference in the cfm the Pro-Filer's flow. Look at the heads Skip White compares the NKB's against. Pro Comps are one of the worst heads on the market. Why not use a Dart Pro 1 in testing?

 

That would be a better option & would get you into the 10.6:1 range.
It's the same head as was linked earlier,but,Skip uses a valve with more dish to it to provide some additional volume.It would certainly be an option.
What machine work has been done to your block?Have the decks been cut?You will need to measure the piston to deck hgt with your new rotating assembly to get an accurate answer & then choose headgaskets,etc to achieve the best quench distance possible.


As for your intake,I'm not a vette guy,so,I'm not sure what the maximum hgt you could use is.I know Brodix has their HP1 intake & it has a hgt of 4.25",which,IIRC,it just barely shorter than the regular Performer intake.
Have you considerd possibly adding a small scoop to your hood?

 

every point of compression below 13:1 is worth 15 HP. Dont sound like much but its enough to feel. The motor will not actually have 11.12:1 since its going to need some cam to reach 400 hp and that cam will often lower the DCR to a very low level. But we have not got that far yet. I would not buy any head until you can figure what cam it will take to get there.

There is always a little more volume than is figured. Check the link i posted from the jeep forum you can see lots of little things control compression and i left them blank when figuring the static compression of 11.12:1

But 10.5:1 will still be fine. Will also still be about the same as 11:1.

With the torker II it will fit the hood but its intake ports will not cover the ports of the 195 cc heads in most cases its a poor match. Would work fine for oem heads but might be a tough fit for the larger heads. Since the ports are so small.

A spacer of 1 inch may fit onto the shorter intakes and help a bit but its more of the port size than anything. Of course volume is still a major issue.


With this cam and 64cc heads I get DCR 8.47:1 with proper quench of .040"

Thats about as close to the sweet spot as you want to get on the street. Cam is about as small i would think could get you to 400 hp level. Should be a blast to drive as well.

BareBones Retro-Fit Hydraulic Roller Cam - Chevrolet Small Block 278/288 - Lunati Power

This is one of the cheaper lunati rollers that should work well for your needs. If it falls short should still be able to go with 1.6 rockers to beef it up a touch.

Should also allow a good timing curve from re curved HEI dizzy. You will need to upgrade the distributor a bit but that will be common to ny engine that is going to make good power.

9:1 DCR is max for aluminum heads and many have gone well beyond this point but it should not be needed for this build should put you right into the best performance for the least headache range.

You could go lower if you want but not sure its going to help the larger cams required to make that power level. So I will leave it up to you.

I posted parts i did the math on and checked to be sure it will work.

The jeep strokers link has a very nice compression calculator and also figures dcr. Just use the advertised duration as it says in the directions should be fine.

I think the blueprint head is a vortec style head and needs center bolt valve covers and vortec intake pattern and headers. But not sure something to find out before ordering. Not sure of any vortec bolt pattern intakes that will fit under your stock hood. But it may be drilled for both just dont know. I also have to say if blue print told me they cast this head from old beer cans they collected themselves i still would think they purchased them from someone else. There clean sheet of paper head is kind of hard to believe. I guess its possible but would put my money into one. But one of the guys on this site recently used these heads and had issues with his accessories lining up maybe contact him and see how he likes them.

Here you go he got the answer in the last part of the post.

http://www.hotrodders.com/forum/accessory-brackets-not-lining-up-new-engine-466698.html



Well thats my two cents enjoy the flame war that will follow. PM me if you have any questions. Probably wont post any more since things always seem to get out of hand here.

Thank you for your two cents!! I've noticed discussion can get out of control on here, but so for they have been helpful.

 

I've read that a Edelbrock Air Gap RPM #7501 will fit under the hood if you use a drop base air cleaner assy.

This is more a project to show my son how to build an engine, but while I'm at it might as well make it a Hot Rod!!

 

Are you going with a roller cam/lifter setup on this build?

 

That that depends on my brother in law. He said he had a set of crower roller lifters. If he don't I'll probably go with flat tap lifters........probably, nothing is set in stone on this.:mwink:

 

I have a complete 6.0l engine I thought about using but wanted to keep the original block in the car. (car only has 65K miles)

 

In the original post you had a goal of 400+HP and you were already committed to the 383 build. You've been told about alot of ways to blow right past your goal and I know it's easy to start changing your goals once into the build process. I'd strongly recommend to keep your goals that fall in line with your budget - I've veered off the original path once or twice and it always seems to lead to either disappointment, delays or both.

A set of budget NKB heads, Profiler, Promaxx, Blueprint, Vortecs, etc are going to blast you past your ORIGINAL goal. Spend the additional money on the roller cam setup for longevity so that yo and your son can drive this car for the next decade with no fear of major failures. Build it on the 'mildish' side and enjoy. A 425hp or so C3 Vette is no slouch now and won't be a slouch 20 years from now either.

Help your son build another car with a stronger effort motor in a more HP friendly/budget chassis later - you'll still have the Vette then.

Jim

 

What the 383 is going in.

 

mta, spend the extra cash on your heads. The heads is what makes the power. I would purchase a set of Pro-Filer heads with 195cc intake ports, 64cc chambers unless the compression needs to be lower. Straight plugs with 2.02/1.60 stainless steel valves. $1263.72. How much do you expect to spend for a set of heads that can produce up to 550 hp? A good roller camshaft and a set of these heads along with a quality short block that has a 10.0:1 compression ratio is all you could ask for.

 

couple comments:
You did not say what the application was going to be? A corvette is a road racing car even though the C-3 does not handle all that well. If it will be driven with spirit in mind as apposed to drag racing the rear gear ratio is not part of the engine build. When building a performance engine you start with the heads not the bottom end. The power comes from the breathing of the engine. There are a few "stock" hoods that have more room under them than the flat hood. Like Richard mentioned, the correct hood is good for 40 hp(indirectly).

I would start by looking for a deal on a set of heads that suits the power you want/need. If its only 400 hp then you could use stock GM vortec heads. If you spend the 13 bills on profilers you could build an extremely nice 430 hp engine That would match that car perfectly.
Profiler 195s, a small "solid flat tappet " cam that would hint of the muscle car era and not have the terrible idle qualities of a fat hydraulic flat cam that makes less power. Set compression ratio at 9 3/4 to 10 1/4:1 for a daily driver. Rpm intake and a 750 cfm carb(hopefully Holley double pumper or something better. 1 5/8 long tube headers. This engine would make use able power from when you let the clutch out until 6k(with a small solid cam) And I don't care if you have 2.73 gears it will work.
Cannot choose cam specs until you pick the heads!
cannot pick the rotator without have head specs available. You will need a good free flowing exhaust system that is also a bit louder than stock to enjoy the stereo at W.F.O. jaunts

 

Lots of good information coming in and I appreciate it.
Sounds like I need to do a mid-post update of my plans for the car.

1: I have no plans to replace the hood or modify it in any way. This is a nice all original car and I'm planning to keep the body that way.
2: I'm not building a racecar and that's why I'm not worried about squeezing out every bit of power I can from this build.
Sure I would rather have a 550 HP motor but I'm kind of like Mr. Crabbs on SpongeBob "I would rather have me money".
3: This car is just a side project to show my 14 year old son how to build an engine.
Most of Y'all's ideas are mild compared to his. He thinks we need a supercharger.......

When it's all said and done this will be a weekend Hot rod and will probably be sold in a year or two.

 

Eagle rotating assembly is installed with piston to deck height of. 025-.027. Pistons are Speed-Pro H860CP30 +5.00CC.
Looking to now use, NKB 200cc/68cc aluminum heads setup for roller cams with Fel-Pro 1094 head gaskets. That should put me at. 040 quench.
If all the above looks acceptable, let's talk cams!!

 

What do you think about this Voodoo?
Advertised Duration (Int/Exh): 270/278
Duration @ .050 (Int/Exh): 219/227
Gross Valve Lift (Int/Exh): .515/.530
LSA/ICL: 112/106
Valve Lash (Int/Exh): Hyd/Hyd
RPM Range: 1800-6000
Includes: Cam & Lifters (#72330-16)
Part Number: 20120711LK

 

I saw the increased lift but failed to notice the decrease in duration. Looks like the larger barebones is still the better choice.

 

When comparing cams,you want to pay more attention to the @ .050 durations than the advertised durations.A good example is if you look at the smaller of the Barebones & the VooDoo you linked.Looking at the advertised durations,it would appear that the Barebones cam is larger,so,you would assume it would make more power.However,when you look at the @ .050 specs,they are almost the same.With 1*.In this case,the VooDoo would actually make quite a bit more power tho,as it has more lift & it has a more aggressive lobe profile that will make more power under the curve.It will however,be harder on your valvetrain & parts,due to the aggressive profile than the Barebones.
While the Barebones cam may get you into the 380 HP range,that VooDoo will likely get you very close to your 400 HP with all the supporting equip.
Tho your compression is a little higher than I would like for this build,it is not a deal breaker,even with the smaller cams.Either cam should work well & allow you to tune for max power.You will still be in a safe range for pump gas & aluminum heads.


Using a bigger cam to prevent excessive cylinder psi is not a good way to go about things.I would much rather see you use a larger chamber head,or,piston choice for this build,rather than trying to crutch it all up with a cam that may not be what you want.Also keep in mind that if you have retrictions on the intake & exhaust,a bigger cam is not gonna make up for that.If the air can't get in & can't get out,the bigger cam is not gonna fix that.

 

You didn't seem to be worried about his compression in post #11 when you told him that his 11.2:1 was "perfect" & of no concern at all,"rite where he needed to be" & this was before a cam had even been discussed.Or...was this just to make up for the fact that you recommended a head without even looking at his combo & pistons before throwing that head out there ???Now suddenly you seem to think his 10.6:1 is too high & is gonna require a bigger cam with more duration than it would actually need to hit his goals ????? Not to say that the bigger Barebones won't work well.Because I never said that,even tho you try to imply that I did.I was just advising that any of those cams would work & that he didn't HAVE to use the bigger cam for the purpose of his higher compression & that doing so for that reason was the wrong way to go about it.

 

I also find it very convenient that even in this thread(post #11 again) you throw that Jeep calculator out there as always & laud it's accuracy,but,now,suddenly today,since it doesn't support your advise & info,(8.6:1 DCR vs 9.3:1)you want to suddenly consider the @ .050 timing which will always show a higher DCR & use it,just to make yourself "appear" to be correct.


What a tangled web we weave.
The truth is always easier to remember than BS.