[old31]

I have been reading as much as I can on rear mains.

Please bear with me on this, as I have never worked on this before.

1: One thread said to drill out the 5/16 oil tube and re-thread to 3/8. Is this necessary?

2: Another thread mentioned, and I did not understand what they meant. If the rear main was removed it could not be installed properly because the alignment will not be correct.