For a stock 302, that will be a bit rich on the main jets unless you've over-bored, good cam, put in dual exhaust and long-tube headers, and a great ignition, advance curve in distro. Also depends on altitude. For stock try .64s maybe. At nearly sea level, I ran .68s just fine on my 68 Cougar and it's built up for low and mid range per my list in the first sentence. Now I live at 4500ft and it might be a tiny bit rich but not bad enough to bother..for performance, you want it a hair rich....my hot ignition will fire through it just fine (capacitive discharge). Your pump nozzle is also rich....it will fire rich early and huff out mid way through....might feel like a bog on acceleration. I think I tried .25 or .28 and worked better....but I'm over 40 and can't remember exactly. Vacuum spring might be a bit heavy, try a brown or steel (clear). On my Bronco, it has Duraspark ignition, Blaster coil, duals with stock manifolds, Mustang GT aluminum intake and who knows for cam...probably stock....C4, 3.50 gears; I'm running .64s with a steel (clear) spring. Can't remember the pump size. So far it's running good. I've kicked around trying the brown spring but that really shuts the carb down, and trying .66s. The black spring shuts the carb way down to like a 2 barrel with an occasional partial opening at WOT. Some guys are saying that it works for them, though.
OK, I'm rambling aimlessly now!
Cheers,
Mikey
