1988 Isuzu Trooper diesel conversion

As usual, click images for larger versions.

The drivetrain is in except for the driveshafts, which have been modified and are ready to be reinstalled.

The top shot is of the transmission crossmember. It is symmetrical about the long axis with the exception of the extra set of mount holes drilled in an extended area shown at the lower edge in the photo. These are the mount holes needed to mount the diesel transmission, as mounting the engine using the stock diesel mounts places it about 1-13/16" rearward of where the gas transmission was.

The crossmember needs to be rotated 180* and reinstalled to use these extra holes. There are driveshaft cutouts on both sides of the crossmember, as well as bolt holes for the bash guard (although they aren't tapped on the unused side, so I'll have to figure something out - large sheetmetal screws?) , so it's obvious Isuzu meant for it to be flipped around depending on application. This is the key to a bolt-in installation.

Second shot is of the three jacks it took us to get the transmission installed (black jack under bellhousing is barely visible). The diesel bellhousing has got the starter motor 'bump' on the opposite side as compared to the gas unit, so simply lifting the transmission up and in results in the bump hitting the body of the truck before it can mate properly with the engine.
The procedure to get it installed correctly requires the transmission be rotated as it is raised. We accomplished this by using three floor jacks, two large (3-ton) and one small. The large jacks were positioned under the bellhousing and tailshaft, while the small one was under the transfer case to be used as a rotational aid. I still had to lay underneath and bench press the bellhousing to help it rotate and to check alignments.
The transmission should be rotated about 90* clockwise (looking at the flywheel side of the engine, which is where you'll be when doing this!) so the starter bump is up in the tunnel of the body. Get it as close as possible, then rotate the transmission back until it's about 45* past its normal mating position to get it the rest of the way in, rotating it back to the correct location as it's shoved onto the clutch assembly. This process is a pain, but it won't go on without rotating as it interferes with the body.
I also pounded the exhaust shield back to allow for more clearance. Another trick we employed was to use a long 2x4 board to lift the transmission up before sliding the jacks under it (one end of the board stuck out on either side of the truck, so 2 people could grab the ends and lift the transmission up).

Final shot is of the diesel transmission sitting on the (rotated) crossmember, using the stock mount.