does d80e stock heads repond well to porting?

[smokedchevy]

Alow me to try to explain my gibberish!! LoL....D80e stock heads will probably flow around 140-150cfm at .500 lift. Since your cam is opening the valve at a max of .488, it'll probably be a little lower. Without flow testing them, we wont know. A stock 302 with e7t heads will flow around 164cfm. Considering airflow with e7t's yields 220hp...the smaller d80e head will make less power. The stock roller cams are very efficient in the 302. Your cam is slightly bigger, but the head does not flow as good. If your buddy gets em to flow better, over 164cfm you'll be able to make more power. The fact that you have higher compression and a bigger cam will yield more power, but those heads are going to bottle neck you. I figured, with the baseline of 220hp, add some power with the intake, cam, and compression, but take away power with those restrictive heads. My guess around 270 hp.

The highly sought after GT40P heads flow around 190cfm at .500 lift. Those heads flow nowhere near enough to make 400 hp. The edelbrock Victor Jr flow 266cfm @ .500 lift and 288cfm @.600 lift. They pick up another 20cfm by getting a cam that lifts the valve another .100". Beyond that, getting a bigger cam will not yield the flow to offset the radical cam design.

Getting a 302 to make 400 horses will require making 1.32hp per cubic inch. That's alot!! If it were a 460 big block, that'd be equivalent to making that engine make 607.2hp. That's a pure race motor. In your particular combo, the compression is there, and that manifold will probably do it. In my humble opinion, you're going to need a bigger cam and a set of Grade AA heads. Whether it be Victors, World Sr, AFR 185s, etc.....