It’s a 451 and am running a Holley 950 on it. I’ve tried a number of things but am having trouble with it back firing through the carb when I mash the throttle. This carb ran great on a buddies BBC with similiar cubes and a big solid cam.
I'm assuming nothing was changed on the carb from him to you. at what RPM are you mashing it? vacuum leak? at the offending RPM is the carb being delivered enough fuel? A locked dist means no vac adv so no potential rotor phasing issue (near zero vac so a can loses its timing/rotor phasing shifts back CW). can you run it up to the offending RPM in your driveway & mash it & check the squirt? (fuel delivery needs would be less than a driveing mashing but it'd be a start). Keep us posted.
