Originally Posted by lust4speed
You are very close with your static compression ratio estimate. I came out with 10.35:1 using your supplied info. Aluminum heads require an additional point of compression over iron heads because of their ability to suck heat out of the combustion chamber so you are completely safe. An 800 DP is way too much carburetor, and no reason for a double pumper on a street vehicle. Holley backs this up on their website recommendations stating that a double pumper needs a light vehicle, loose torque converter, and lower gears. It's not sexy, but a 750cfm carb with vacuum secondaries will be much more efficient on a 406. That translates to more power and much better gas mileage. I would also come down a notch on the cam choice. The 230/236 duration @ .050" is a little rowdy for a 406 in a heavy vehicle. You should also have a higher stall converter over stock, and vacuum for your power brakes will be marginal. While the cam would work, I'd just go somewhat smaller for a heavy vehicle.
yea i get what you are saying, ive changed most of the things i said in that first post already. But yea, i will probably end up with a 750 holley. But you are saying that i should be okay because i have a aluminum heads? ive heard that but never knew why, so since its taking heat away its essentially lowering the compression in the cylinder?