I'm trying to picture where your screwing these longer studs in for guide studs...???
Last and every 8 3/4 I ever messed with the studs were pressed in with a knurl from the inside. 64 up anyway...
That means the pig is already out and on the ground again to get inside the housing to swap out the studs to longer ones...Sure will make fixing the leak easier...
I understand most here have great intentions when offering advise...but damn...To someone whose never done this and is truly trying to learn he is unbelievably confused now...