1962 Impala 283 12 MPG
I bought this '62 hardtop in March and finally able to drive it: it had numerous oil leaks like back of intake and incorrect spin-on conversion, , had a loose pilot bushing due to over-size hole in rear of crank, had old floppy center driveshaft support, had truck bell housing with too big center hole, had leaky pinion and tranny rear seal, had heater valve drooling antifreeze, ect ect ect.
Engine stamping F0205E and casting 375619 so a generic 283 but don't know current displacement. Runs strong and smoke free so had to be overhauled recently. Probably a mild cam. 3774682 casting on heads. headers and glass packs. Edelbrock 3X2 W/Rochester carbs a professional setup obviously with anodized throttle hardware, no-idle bases front and back.
I wanted to drive it to Impala convention in Iowa next week but it always gets 12 MPG and that's the best it gets. The rear (I VERIFIED 3 1/3 turns) is 3.36 as it was originally a 3 speed on the tree. Currently i installed wide ratio Saginaw 4 speed ( 3.5:1 1st gear so i am looking for a 3.08 gearset).
I have front and rear carbs blocked off, i have re-jetted center carb from #55 to #52 as this is what my old 1965 283 from high school still has. Now i disassemble again and notice the power valve has a nipple only 1/2 as long as typical, and the 'nail' pusher has a spring with only about 23-25 turns instead of typical 31-33 turns. Obviously someone has been here before me... The elevation here 57703 is 3200 feet, the RPM at 65MPH on the tach is about 2900. front tires 225/45Z18, rear tires 275/40Z18. all at 32 PSI. Stock dist with Pertronix III rev limiter set to 6200 just to eliminate it, initial advance at about 6 and i run direct vacci to the dist not ported vacci. I know i wont get 22-24 MPG but come on its just a 283 that feels and sounds like a 250 HP 327, if i can't get 15-18 it stays at home. Any help or suggestions appreciated...