400 sbc heads

What is the best set of heads for a 400 sbc? casting number 3951511
i want a mild build with decent torque and horsepower.


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you sure the # is right ,, cannot find that #. Most 400 engines were lo comp and detuned for emissions.

Vortec heads work very very well for this.

Bone stock L31 Vortecs. Casting number 12558062, rescue from the boneyard, disassemble and magnaflux for cracks. 5-angle valve job, new seals, drill for steam holes.
http://www.gregsengine.com/350to400.htm

Bore block 0.030", deck for 9.008" block deck height. Install Keith Black 30cc KB126 pistons on 5.7" rods. Fel-Pro 1014 head gasket. Zero piston deck height with these components and block at 9.008" with 0.039" squish and 9.1:1 static compression ratio. Edelbrock RPM intake with 650 carb. 1 3/4" equal-length, long-tube headers. CompCams 12-234-2, XE256H cam, 256/268, 212/218, 0.447"/0.454", ground on 110 LSA, installed 2 degrees advanced.

This is a daily driver grunt motor that can be operated with a stock torque converter on 87 octane swill. The power is all done by 5000, so will work well with a stock rear gear. Check out the torque at 1500.
RPM HP TQ
1500 120 419
2000 171 449
2500 213 446
3000 263 460
3500 310 464
4000 341 448
4500 353 412
5000 318 334

Mate that to a 2500 stall conv. and 3.73 gears and invest in some stock of your favorite tire company- I predict their sales will be going up.

I would have narrowed the LSA a bit, but it is a GREAT example of very streetfriendly power. It'd idle like a caddilac too.

Now you're cookin' with gas!!

I have a Vortec headed 400 with a 268 High energy comp cam that specs 218/218 @ .050. It runs about like Tech inspectors simulation. It is good on fuel and passes emissions. Having said that think about what you might do with the vehicle and parts that you have now. A set of Dart Iron Eagle platinums in the 200 cc size will still make great low end torque and make more power at high rpm. It is just something to think about.

How good is good?

Shane

thanks everybody the 350 to 400 really helps