Thrust bearing cap offset
Crash520, I have a very similar issue, with a 318 mag and arp studs. The top cap bearing thrust surface is tighter on one side than the other by .003 or so.
Goofy Thrust Bearing Gaps
I haven’t been able to correct it yet (time)
Also, a torque converter will thrust the crank foreward. More so if you’re putting a lot of power and pressure into it.