In the realm of the possible? An impossible dream? Pure lunacy?

I know that the what manifold / cam question gets raised frequently. Sorry to do it again. I have a moderate amount of knowledge on the SBC but I just can't seem to make up my mind on cam/manifold combo. Perhaps you can help me.

I'm going to build a 350 for a 1970 Nova with stock rear gears, turbo 350 w/ stock converter, 600 holley vac secondaries, ~9.5 CR, HEI, headers and duals. Won't be revving much above 5500 RPM.

The engine will have to deal with a stock bottom end and the stock heads with new springs and a inexpensive clean up and perhaps some light porting for the time being (will pick up a set of brodix IK 180s in the following summer season).

I've got the cam selection down to Comp Cam XE262H or XE268H and manifolds down to the Performer EPS or the Performer RPM (likely not the air variety of each).

I hope to use the car regularly during spring, summer, and fall with only the odd trip to the track so I don't want to totally kill my gas mileage. I had a 396 in a 1970 Monte Carlo and just couldn't deal with the gas consumption.

It seems obvious to me that the XE262H would be the best for around town driving between the two but, as silly as it seems, I want a rough idle because the sound of these classic cars really adds to the whole experience of driving one.

Seems like I could go with either the EPS or RPM with the 262. The 268 looks to be better matched with the RPM (or would it not be so bad to use an EPS).

Last, would there be much of a difference mileage with between the two manifolds and between the two cam choices?

Any other tips, outside of the obvious, for achieving better mileage?

I really appreciate you feedback.

Cheers,

J