Re: Tex, headers
I'd go with 2-1/4". That's what I have on my driver with a TBI 350, RV cam and factory manifolds. For a driver you need low end torque and smaller pipes are better for that. Call Flowmaster for another opinion. Hedman headers are a good value - not cheap on quality, but fair price. I have a set I used to use that have held up great for several years. They go for about $100 for a set for a full size Chevy. I'd go 1-5/8" on the primaries, which is what you'll find most available.
'84 K20 driver
<font color=orange>'79 K10 mud racer</font color=orange>
'48 CJ-2A trail Jeep