The "In over my head" build thread

[SeventyOne]

Frame is basically ready to go out to the powdercoater but I have some concerns before I send it.

I will be running a 700r4 and will be moving the engine forward 1 7/8" to accommodate the extra length. I will also be using the DIY crossmember. Should I find the exact location of the crossmember before I send it out for coating? Basically mock up the engine and tranny then tear it down once I know the new location? Or just measure and drill then send out the frame?
-Reason I ask is because yesterday I attempted to mock up the drivetrain and ran into issues across the board: frame seemed to have "shrunk" slightly (frame rails are closer together than before) since the tranny x-member holes are tough to get aligned. Then, the 700r4 seemed to mount differently to the crossmember compared to the Th350 - the mounting holes on the end of the tranny seem rather small in diameter. Maybe I need 700r4 specific mounts/bolts?

Also while mocking up the DIY engine crossmember I tried putting the poly bushings into the tube and they are extremely tight and the bushing won't seat fully in the tube - to make matters worse I can't get the bushing out now. So I can't mock up the engine, and later I need to remove it so I can get it coated but can't. Awesome.

At this point I stopped from severe frustration and daylight running out...

Maybe I ran into all these problems because I am trying to reassemble some 40 year old parts with some new and some aftermarket parts? If anyone has some words of wisdom here I could really use a little advice from those that have been here before. I know there's a lot going on in this post but any help is appreciated.