another thought . . .
Welcome!
If you don't have one already, and you are dropping the gas tank, get a 255hp fuel pump. Peace of mind and fuel support up to 500 HP.
Also a good opportunity to replace s spring and re-pack clutches in diff.
If, however you are wanting to do hg or motor work first, it might be just as easy to at least partially remove motor instead of disturbing the rear end.
I went ahead and pulled the motor and replaced the rings and bearings in mine, the originals were in there with 186k copper exposed...
Plan for about $300 in gaskets and engine parts if diy...
paul