What's the main differences with these? Can these be swapped in place of each other?

 

They are the same basic transmission, the 4L60E is the latest version, and is electric shift etc. Its easier to swap a 700R4 for a 4L60E than it is a 4L60E for a 700R4. There is also the 4L60 which is just a renamed 700R$ that cme in between them. I don't know why anyone would want to swap one for the other anyway.

 

A 4l60 is a 700r4. The only difference is it's dependent upon a tv ( throttle valve) cable. The 4l60e is just an electronic version. If you put a hydraulic lock-up 700r4 in, there will be no issues. The truck may throw a ses light though. FWIW a properly built 700r4 ( like I recently put in my procharged silvy) can and will handle quite a bit of abuse. I'd do it in a heart beat if I were you. Find a 88- 91 four wheel drive core and have a reputible transmission shop build it with top of the line parts ie: alto red eagle clutches, kolene steels, torque drive hardened input/ output shafts....the list goes on and on. It will handle just about anything you throw at it. You will need a different tail housing if you use a 4X4 case, but it will be exactly the same dimensions as the 60e.