What MPG are you guy's getting, What combo/

318 .30 over
ld4b intake 650 carb
675 casting heads 1.88 / 1.60 mild porting, .039 head gasket.
windage tray
340 purple cam, not degreed, double row timing chain
timing set at 36 degrees, with vac advance.
overdrive 4 speed with 26 tall tire and 2:76 gear.
I can knock down about 22 MPG on the hwy and about 15 in the city.