360 driver build

I'd run the 2.02s. Mainly because you can drop them on fresh seats without sinking the valves. That is worth low lift flow, and the stroke is much more of an effect on port velocity than the valve size. You should have no trouble getting 20mpg on a 360 in an A body, but, you will need a high rear axle ratio, 2.76 or 3.23 with a decent hieght tire, and a tight, lower rpm stall convertor. As a comparison... I built a 422" 340 based stroker, with ported iron heads, 2.05 int, 1.65 exh, open chamber, 9.5:1 static. With a hydraulic cam around 242°@.050 and a Holley 870 Street Avenger, it pulls 17mpg when he drives it from NH to Carlise PA. That's in a 3800lbs e body w/3.23s and a 2200 convertor. It also runs 12.80s at 109+, on pump gas. It's a mild stroker but it's a very efficient package. So make the engine work in the right rpm range, gear and stall it to keep it in that range and efficient, and I dont see where 20+ would be not reachable in a car that weighs 500-600lbs lighter.