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Discussion Starter · #1 ·
I am finally going to get things moving on my 1970 Monte Carlo. I have the option of getting a turn key 383 crate engine, or rebuilding my 400. My budget for the whole project is around $7000-$8000 for everything.

Car: 1970 Monte Carlo

Engine: 400sbc 2 Bolt main. I have Stock: Block, crank, rods, pistons - that is all.

Transmission: Mildly built Turbo 350. No TC (3500 too much? I have one).

Rear End: Factory 12bolt with stock gears no posi. (3.55?)


What I want: I want a car capable of being a daily driver with good torque 450-500lbft and decent hp at least 400 - 420hp.
This car must be able to run on pump gas. And must be able to do 75mph on the highway all day.

I am open to rear end/trans changing suggestions but remember this whole build must stay under $7000. The car is in great shape other than having no engine. It does not need anything more to "drive". I am ok with keeping the Turbo 350 and stock gears if a 406 will pull good with that set up as a "get it" motor. I don't want a high compression High rpm motor. Im ok with a 6,000 redline. I just want good torque and decent hp.

Please include a parts list for suggestions on the build if you have built something similar. Thank you.
 

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profiler 210 cc heads, 10:1 cr,mild hydraulic roller cam around 225º [email protected] with .535 lift on 108/112. Performer rpm intake,750 minimum cfm favourite carb, 1 3/4 " primary tube headers. Depending on what you have to work with should be way under 7k? buy better rods than stock,balance and minor blue print of engine. May have a slight bump in the idle,should pull to 6k with the tires melting through first and second.with your 3.55 gears you will want an over drive transmission.You wont need a 3500 stall unless you plan to drag race. You will need a posi as this will eat tires
 

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Discussion Starter · #3 ·
I plan on putting posi in it or 3.73 gears with a 4spd. But like I said, cost, and I'm not sure on the rear ratio that's in it now. I've also talked about 5.7 rods to replace the stock rods. The $7000 takes into account fluids, ignition (plugs wires dist.), fuel pump, carb, headers, TC, tune... This engine has to have everything because I have nothing but the long block and old rotating assembly. If I go with a 700r4 I will have to modify the driveshaft and get new linkage. I can't do that myself so labor is a factor.
 

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its less than $200.oo last time I had a drive shaft shortened and balanced. With all that you listed you should make it. 2500 stall is enough.If you go a stick and 3.73 gears then over drive is a must. The stock gears are fine with a 4 speed that has a low first gear.Talk to Autogear.

I dont know why 3.73 gear is so popular? lol.
the replacement rods are $350.00 ish for this mild 440-460 hp 406..Use the factory crank if its in good shape. Machine work will have fixed costs. The blue printing is all yours and where you save a tonne.
 

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Discussion Starter · #6 ·
The stock motor had 80k on it when pulled 3 years ago and still ran great. So I should use the specs from the crate 406 shown above to build mine? or would it be cheaper to just buy that motor?
I have an older guy who runs a very reputable shop who wants to build the motor for me, but I always wonder about these older guys knowledge on new and cheaper technology and if they know they can get higher numbers than they think. So 700r4 with the "Stage 1" 400 build is my best bet?

So far his idea has been to build what he calls a "get it motor" with ""vortec"" heads, 5.7 rods, and a bigger cam. 10/10 rebalance and grind the crank he says. I don't think those heads are as big as 200cc and 64cc

Just so yall know I am fiarly knowlagable on cars and engines, but when it gets into the detailed numbers on certian things like regrinding a cam or valve numbers it's better to give me a part number than throw the number at me, and thanks for the links.
 

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Why not go LS? you can buy a wrecked truck and swap everything into your car for less than 7000. You could even throw a cam in it. Then you will have OD trans, EFI and about 20 MPG. Just a thought.
 

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Discussion Starter · #8 ·
I haven't really thought of that. Are you thinking 6.0 4l80e combo? I just want a reliable rig, so I'm hoping for all new everything. I don't know how much wiring/modifying I would have to do for that engine and trans.
 

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a ls 6.0 that gets 20 mpg???? I wanna hear more!!!!
the 6.0's around here, won't get 12 mpg on a good day.
the 5.3's will barely get 15.
the 4.8's..............well, they won't pull any weight at low rpm's, so kinda useless in a DD truck.
but I would like to hear more about that 20 mpg ls motor.
 

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some thoughts...

The 6.2 LS in my 6500 LBS Escalade gets 17 on the highway and 12 around town and I usually drive around with my family of 7 and some stuff in the back. If setup right an LS in a 3500 lbs Monte it will get 20 MPG easily. I dont think you can do a LS right with a trans for 7k though.

As for a budget build...a 4 speed auto will offer you the quickness off the line and docile cruising you want. The least expensive way to get this is with an LT1 and 4l60e package from a 93 to 95 Impala, Fbody, Buick Roadmaster and full size Caddy. These are the pinnacle of SBC technology and the 4l60e from those years is pretty dialed in. An LT1/4l60e package and stand alone harness with PCM should run you 2500 bucks, add in some roller rockers and an mild upgraded cam and you should see a very useable and bolt up 375 HP package for a total of 3200 with gaskets. It will have perfect drivability and road manners too. That will leave you with lots of cash left over for details and maybe a 383 rotating assembly next year. Find a good motor and pickup a harness/PCM package on ebay and your Monte could be running in 2 weeks. A lightly mod'ed LT1 with 4l60e will slightly outrun a 400HP/383 with a TH350.
 

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Discussion Starter · #11 ·
I'm just very hesitant to buy used parts. Wont I need to modify the car to fit and use a 4l60e? and I would appreciate more advice on the 400 build as that is what I came here to ask about originally. I now know it will be worth it to convert it to a 700r4. So I've settled on that. Throw some more parts and numbers at me for the 406. I guess I should be looking for around 400hp and 500ftlb of torque. This is an almost 3,700lb car.
 

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I'm just very hesitant to buy used parts. Wont I need to modify the car to fit and use a 4l60e? and I would appreciate more advice on the 400 build as that is what I came here to ask about originally. I now know it will be worth it to convert it to a 700r4. So I've settled on that. Throw some more parts and numbers at me for the 406. I guess I should be looking for around 400hp and 500ftlb of torque. This is an almost 3,700lb car.
I hear ya but getting a 700R4 rebuilt to live behind a 400 will cost more than you think, then you'll be messing with the govenor for months to get your up-shifts and down-shifts right. And after all that it might live for while and since you messed with the gov who ever built the trans wont warranty it. Good luck! All things considered...Package always beats cobbled.
 

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not sure what I left out or why you made no comment on my build? The details need to be figured.My 440-460 hp combo will fly. I hope you understand what I posted?
 

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a ls 6.0 that gets 20 mpg???? I wanna hear more!!!!
the 6.0's around here, won't get 12 mpg on a good day.
the 5.3's will barely get 15.
the 4.8's..............well, they won't pull any weight at low rpm's, so kinda useless in a DD truck.
but I would like to hear more about that 20 mpg ls motor.
Really? You're surprised a 6000lb truck shaped like a brick doesn't get 20mpg?

He's putting that engine in a 3500lb car not shaped like a brick. Corvettes routinely get 20mpg. My car has an LS1 with heads and cam and I get 18 mpg with a 700r4 It's not at all unrealistic to think he'd get that mileage out of that combo
 

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Pro-Filer ECONO start here,,,

you need to do your own math. I didnt say 64cc combustion chambers(it depends on what pistons you use)I said 10:1 cr. Thats a street friendly compression ratio.You have heads that will produce from 500-600 hp.You want an everyday 400 plus and lots of torque?

to help with your math,,, every cfm of air flow on the intake side can produce more than 2 horse power or a bit more. The 210 cc volume on the intake runner is a moderate size head that would work great on a 400 cube engine but too big for a 283,,,You need to nail down exactly what you want/need and match all the parts for that number.
The numbers for power I gave you are conservative and you could easily exceed them. Some members will be very optimystic with their power predictions.

Read up on profiler heads,they are a bargain for what you get. The cheaper heads mentioned above are not CnC ported
 

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raid magic, mpg is in direct proportion to horse power required to achieve the speeds you need combined with SFC,nothing else. A stock cammed LS,especially the lower rated power engines get" better " mileage because they are driven at lower rpms due to the overdrive. The fuel management system is FI on an LS and they can be run leaner under cruise conditions than a carb.Computers do help when it comes to doing a better job of tuning than the driver of a carbed engine. An LS engine converted to carb would not get better mileage than a gen 1 sbc. If you put FI on a gen 1 sbc then you have the same advantages. The LS engine comes from the factory with heads that flow better than stock gen 1 engines,the profiler sbc heads flow better than LS heads. Use the retro roller cam in the 400 and now the stock LS roller cam can be duplicated or improved.

The 6.6 liter gen 1 400 is bigger than "most" LS engines so now we know where more power will come from
 

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Discussion Starter · #19 ·
Thanks for all the info. Im not super worried about the numbers for hp as long as both or at least torque exceeds 400 before 5500-5700 rpms. I know the 406 can pull big block torque numbers pretty easily.
 

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Discussion Starter · #20 ·
I just talked to they guy who I've been working on putting numbers together for the build, and he said he plans on using 64cc "fuely" heads. These are corvette 327 heads cast. I'm wondering if the build he's put together in his head is going to be too "olds school" to put out the power I could get from what ya'll have shown me.
 
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