68 Valiant Hellcat Swap

The should is coming along nicely. Very well done. Maybe I misread it but if you refused to two mounting bolts that had to be swapped for the pickup tube that would concern me a bit as they are a torque to heidi bolt and it is recommended they be replaced if they are ever disturbed.
I believe what you are referring to is a Torque to Yield fastener. The main bearing cap bolts are actually Torque to Angle fasteners. Everybody has a different opinion, but I have re-used Torque to Angle fasteners before in the past with no issues.