I'm sorta' doing what you're talking about. I'm in the middle of putting a 1986 C-223 turbo diesel drive train into an 88LS body. I have the 86 Trooper diesel down to the bare frame with just the drive train and gas tank still there.

I've done the research on this so ask any questions you might have.

As fara as the transmission goes, a diesel transmission is different than a gas transmission. The bell housing does not come off for an exchange, so you need the diesel transmission.

My problem is that I don't know if I should pull the drive train out and install it into the 88LS or if I should just slide the 86 complete frame underneath the 88LS.

The 99LS has 89k on it, 86 diesel Trooper has 188k on it.

BTW, I do have a Yahoo forum on the swap called IsuzuTD, if you are interested in checking out the vehicles.

Jesse
Connecticut