[steve25]

I don’t know what your budget is , but for 2700 bucks in parts I would get a Butler stroker kit to make you 400 a 433 to 440 cid motor.

This will work much better with the stock port volume of your E heads , no less if you have them ported to a bigger size then the 215 CC intake runners they have now.



If you port the heads to the 315 cfm level or greater then that RPM intake is going to be a bit of a cork in the
flow system, but you can get the new motor up and running with what you have now and then see if you want to step up to a better flowing single plane manifold.

Your stock rpm intake is good to about the 550 hp level where at that point the Hp numbers will roll off down hill fast.

Since you want to go to a hydro roller I would get one such that once you add 1.65 rockers you end up with .580” lift.
This much lift is nothing for a hydro roller cam and this much lift will also have the positive effect of using more of the flow the head has to offer, and the other good side effect is due to the added flow intake port velocity will be higher for any given rpm the motor may be at which will make for a better overall driving experience.

I have ported those E heads to 340 cfm and they still made great port velocity and would take a 3200 lb car down to 9.13 in the 1/4 mile , but they need to be done right !

With porting the heads your 770 carb will still work good , especially with a single plane intake, but down the road if you still find you want a bit more top end and want to trade off some bottom end power, then a 950 cfm carb would be what I would be looking at!

Note that to run .580” lift those not so great stock E head springs will need to be changed out to a good duel spring set up, and in no springs packages with a flat wire damper should be used.