I have an 86 pickup it has the 22r in it and is 4x4 with the 5sp. I also have an 81pickup with the 22r it is 2wd with the 4sp. I would like to swap the 81 motor into my 86 but I’m not sure it will work. Is there any reason this motor swap won’t work?

 

It will bolt up just fine to your transmission. Swapping early short block for late short block is a no go. If you are swapping the entire motor it will work. You'll need the header from the older block also. The header exhaust ports are different for early blocks (round port if I remember correctly).