[chevyelc81]

Ive got a small block chevy 400ci. Im debating on what size valves I should run with out going over kill, but with out going undersized. I was leaning tward the 2.08 valves that come in the dart pro aluminum heads but I don't know if thats to much or to little. I also found some heads with 2.14 intake valves!!! Here's my application; 400ci with 9 to 1 compression, Crane Cams roller camshaft 256/256 duration with .625/.625 lift, roller rockers, Weiand 177c.i.d. supercharger, 800cfm edelbrock carb, msd 6al ignition, 4-speed short ratio tranny, 3.55 gears. Car weight is 3,400lbs. Any advice on heads would be greatly helpful. Thanx

[johnnymopar]

i say go for the 2.14, everything else is big so stick with the theme!

JB

[4 Jaw Chuck]

Head design, valve design and porting has more effect than valve size, if the heads you buy come with the 2.08 go with them. Going in and putting in larger valves opens a can of worms that will affect your reliability, ever seen cracks between valve seats? This is a very common failure mode with oversize valves. If you are going to do some factory heads stick the 2.02 factory style valves in, a very reliable setup.

[glen trulove]

looking at youre setup your gonna have a big problem with lowend torque. what are u planning to do to the car ar u gonna race the piss out of it. or daily drive it. or both. a big cumbustion chamber with small valves gives u unbelievable low end torque, small chambered heads with small valves, justsucks. small chambered heads with big valves will give you all mid to high range your off the line start is gonna suck but youll play catch up, the best thing to do is be moderate on the heads. get 64 to 60 cc heads with 2.08s to 2.02s this will give you your best performance throughout your run.

[chevyelc81]

Thanks for all the advice. I was also wondering if the bottom end would hold up to the supercharger. I was told if I run a supercharger, I would need to convert the block to a 4-bolt main. Right now its a 2 bolt main. Will it hold up?