thanks. i thought 12 would be too much also. but we started around 5 and worked our way up slowly. it just kept on running better and better. until a little after 12 it started to sound wrong. 12 was were it idled the best and reved good with very little popping and backfiring. any lower it idled worse and would backfire more whenever you let off the gas. the surging also seemed to be even worse with less timging.

i think the edelbrock one is a 500cfm. the other i dont know, but im pretty sure it was just a stock one from an early 80's 350. they both did the exact same thing. you couldnt tell which one was on there by the way it ran.

will try to get a hold of another distributor to test. but this one looks ok, and we replace the cap and rotor. although it is old, so you may be right.