I know this is supposed to be a GM diesel site, and the 6.2 swap would be a great project buuuuut!!!! if you are looking for a brick solid, dependable engine tranny combo you would be hard pressed to beat the Mercedes 3.0 5 cylinder turbo diesel with the four speed auto. They were also available with a four speed standard but these are a little harder to find. These engines consistantly get 500,000 miles before overhaul and match your current engines power output pretty closely. Have seen some that have been dialed up to 150hp but don't know how that would effect their reliability.

The last ones were used in the 1985 123 and 126 bodies and are strictly mechanical. You could expect well over 40mpg with this engine and maybe considerably more. Certainly won't impress the boys on Saturday night but you won't be spending alot of bucks on rear tires.

It is a little heavy but as you say you are doing airbags and the engine and tranny mounts are easily fabricated. Would have to fab up a driveshaft yoke and will probably have to shorten the shaft. These are a high RPM diesel and most probably you won't even have to change the gears in the rear end. They seem to love 3,000 RPMs (about 65MPH) in the cars and redline (governed) at about 5,500RPMs.

Mercedes used a great vacuum pump on these engines and they were designed for vacuum brakes, thus no hydro-boost needed. Wish there was a way to modify this pump to use on the 6.2.

Lots of parts availablity, reasonably cheap, and there is even some hot-rod stuff available. If you do want AC, Mercedes used the same compressor as the older (pre 93) GM trucks and cars.

Just a thought.

Bill