I’ve got an ’86 GMC ¾ 2 wheel drive truck. Runs great, love the truck. I’m on my 2nd TH400 trans. (160K miles), and I’m starting to see signs of needing a 3rd trans. (Slipping, morning sickness). Here’s the question: Has anybody swapped a TH400 for a 700R4 in something like this? What will I have to contend with? I know the 700 is longer so I have to move the trans rear cross member and shorten my drive shaft. What about shift linkage, Speedo drive, vacuum for shifting, overdrive engagement? Any advice what be greatly appreciated.