Adjusted the timing as directed on the 71 GTX. It runs much better, but doesn't spin the tires like it did prior to setting the timing. I also pumped more air in the rear shocks...would that shift the weight to make it not burn rubber??

What was your initial before when it was spinning the tires. What is it now when it wont spin em.

I never use the factory specs. for engine timing.... I always adjust it as far advanced as I can without it pinging.... Once you start putting aftermarket parts in a motor it changes where the motor likes it anyhow....

It was pretty far advanced before..like an inch. My reason for resetting to factory specs was hard starting when engine is warm. Stock 71 440 super commando. Factory setting is 5. I think i'll suffer through the hard starting to be able to spinm. Think a new starter?

one inch clockwise from TDC is 15.8 deg which ain't excessive plus you should be able to see that on the tab & should not be causing starter drag. Not a starter issue if it's OK at one setting & not at another tho a high powered mini starter will push thru that if you're pushing the limits with initial/scr but we're missing something. It's possible the dampener has slipped but that is rare & I'd rather k.i.s.s. 5 definitely ain't enough. So it runs better at 1 inch but the starter is cranky, correct so far? EDIT you can wire in an ign cutout & crank teh car with the key then close the switch while it is cranking. We had to do that on the stock car for it's labored cranking when hot. On/off switch in series with the black wire from dist to coil neg pri terminal (points) or blue/yellow wire to ECU (electronic) but it should not be labored at 15.8 initial plus ain't the 71's low compression?