Hey guys & girls, I was hoping someof you here may have some experience and recomendations on this......

So I had been planning on dropping my spare Humvee 6.2 into my truck (86 GMC 3/4Ton 4x4 6.2L+th400+4:10's+AC all stock) when my orginal 6.2 siezed up. The problem is that when i dis-assembled the Humvee 6.2 to put new gaskets throughout I found spun rod bearings in #1-2 and a badly damaged crank. I just don't want to spend the money this year on a new build up.

So I have 79 2wd 1/2Ton that is very rusty with a bad th400 but a really strong Goodwrench 350DX unfortunately the milage is unknown but speedo says about 150k+ miles just have no idea when the engine was replaced during that 150k so the engine has something less than that, 75-100-125 who knows. it starts easy, runs great, gets great fuel milage.

I see the th400 bellhousings are different on the two trucks and the position of the engine mounts is different, and of course 6.2L truck is a 4x4 while the 5.7L truck is 2wd. It seems the biggest challenge is that bellhousing because of the position of the 5.7 vac pump and I'm not sure about bolt patterns matching up? (5.7 has the dip in the top of the bellhousing, th400 has the peak at the top).

Is there anyway to put the 5.7L into the 6.2L 4x4 truck with the chev th400 bellhousing? Has anyone done this before? Is there anything else to be aware of with this conversion?

This would be a short term temp setup until I rebuild the 6.2L next year sometime.

Also what about fitting a 6.5 TD into this 86 6.2L 4x4 w/AC? easy or hard?

Anything you can tell me would be great, thanks.
Thomas Taylor