Lugz - My speedo cable will be ok I think. It’s likely not the stock length one, there looks to be plenty of slack to move 6”+ rearward.
Dang! on the drive shaft length. I was hoping I wouldn’t have to mess with that.
I went out and got my tape measure and eyeballed things: existing 3 sp with OD - 21 3/4” to the end of the tail housing. The T5 is 24 1/4”, both measurements from the bell housing face that the trans mates to. That 24 1/4” lands halfway into the 1st part of the u joint. I thought it would be plug and play. Oh well, too much in this to back out now, the plan evolves.