I'll be searching for a 2wd 4l80 to swap soon, and keep seeing code MCP or MJP used. From what I can gather, this is only a designation used in the Express and Savannah vans, with the difference being the tail shaft length based on if the van is a longer wheelbase or not.

Anyone know which code is the same, or closest to, the truck transmission? Are there any other differences between MCP and MJP?

I assume since I am a RCSB, and my wheelbase is the shortest combination, that I would get the MCP shorter tailshaft housing or the truck transmission. I'd like to avoid shortening my driveshaft, if at all possible.

 

You will have to shorten the drive shaft any way you look at it. The 4L80E is physically longer.