ive put new bolts, not sure about fly wheel but I will double check it.. previous mechanic used die grinder and slotted old fly wheel so torque converter would fit. it cracked so this is when the problems started. it has had two different flywheels since then. ive been chevy nut my entire life but have never ran into this before..
how do you check air gap?? never heard of that one before....
is there any difference between a 153 tooth starter and a 168 tooth starter??
in my defense ive never messed with any 400s as ive only owned one and it was back in the day when heads were famous for cracking. I yanked it and put in a 327.

I will back timing off and see if i can tell if flywheel may have been installed backwards.
thanks
Larry