1989 700R4 going into a 1984 K20 Chevy Suburban

[62ChevyC60Wrecker]

My 84 K20 Suburban's transmission crapped the bed back in the last week of October; I just got a used 700R4 put into the truck. I was watching "Youtube University" and this channel I was watching the host put up on teh screen the 700R4 had several "generations" on the 27 spline output shaft & the 30 spline shaft was started by GM sometime in the late 80's. I will be counting the splines on both the transmission today (1-1-2024) between the used 700R4 and the NP208 transfer case that backs it. Any suggestions on what to look for parts wise that would be the cheapest way to go as I am doing this on a budget. I am considering getting another driveshaft made; (if need be) and leave the T case out for the winter; although the truck won't be 4x4 this winter. Any suggestions? This is my first transmission swap and I don't have a 2 post lift in my driveway; I am laying on the concrete doing this. I also have to swap out the shaft for the shift linkage that's tied in with the rooster comb as well. I will be pulling the pan off the dead 700R4 to figure out how to disect the one in the truck as the shaft broke at the side of the case. I have the removal and install tools for the seal. Those just came this week from Amazon.