Cylinder Head Swap blues….

So I just finished swapping cyl heads (J's for ported X's) along w/ intake, carb, starter, plugs & wires, coil, alternator and it fired right up! Yea! Thanks to the new mini-starter and carb. Idle's fine and nice. However it's popping/snapping intermitantly when you blip the gas or hold it between 1500-3000. Above 3000 it seems to smooth out (no popping). It sounds like popping/snapping inside the muffler (not a backfire out the rear). I'm thinking it's timing? However I never removed my distributor or rotor (just the cap) so technically never messed up timing. I already checked my wire terminal connections at the cap and plugs, and the routing. That looks good.

Any ideas what else would cause these "misses" or "popping"? I'm going to put a timing light on it tonight, but if it's not that I'm at a loss?
Author: admin