Going a similar route with my H2 that just blew the motor (2 months after i bought it).
New LS3 with a new 4L75, stainless long tube headers, air horns, tuning, on-board air compressor to air up tires, new upgraded radiator and trans cooler. I'm at $23K before any surprises pop up. Oh, and getting transfer case taken apart and inspected.

 

 

Big Power Racing in Bay Shore NY is doing the conversion.
They have an incredible shop and skills.
They put my buddies H2 together. 500 HP and such.

They can even have the transfer case swapped out to 2 wheel drive.

 

Do you have more info on the 2wd case?

 

I don't. They have Facebook page, I'm sure you could reach out to them.

 

Just an update. I'm at 2.5 years since my conversion and I'm overall happy with my build. It's been a learning curve for sure but now with maybe 30k miles and one tranny rebuild I'm still driving it everyday. Since the tranny rebuild I have not done any wide open throttle pulls but I am always accelerating at about 3/4 throttle which still puts a lot of power through the drive train and gives me very fast acceleration. Cooling is still an issue on hot days in traffic so I'm adding an external heater core with fan that should take care of it. This summer will tell. The drive train has had zero issues. Transfer case, axles and drive lines are strong. All in all I think this turned out well. One thing I'd do different is to use the cheaper less powerful LS3 and then I think there would be no major issues...

 

I would recommend you instal a cadillac ats turbo/camaro ss fan like I did. Its a single fan, 20" diameter, variable speed and pulls about 1.1 hp. It will need to be custom mounted, will cover the entire radiator, including the upper and lower tanks, has built in flaps to allow air to bypass the fan (if you go too fast and the fan cant keep up with the air going in) and you will need a special sensor from spal to run it, or use the ecu to control it. It will start at approx 30% speed and ramp up to 100% as temp goes up if you use the sensor. I kept it on the aensor so the fan stay ON at highway speeds because I realized with my thick radiator and small grille openings the fan will still pull air and improve cooling.

 

Is that GM part # 23347101?

 

The one I got was part# 23455465
there are many part numbers that preceed/superceed it but they are just the same. Make sure the sticker on the fan motor has ABL850 (indicates 850 watts). The fan shroud will have a sticker with 850HT written on it.
Besides the fan, you will need the correct plug ($25) and keep in mind its 850 watts so you will need proper wires to handle a 70 amp fuse.
You will need to have the 2008+ ecu to run it directly from the vehicle and set it using hptuners to work using engine temp/ac pressure values or buy the correct temp sensor and harness (approx $150) and run it as standalone, this will allow you to have a manual override too.

 

im doing one for a cutomer and running into clearence issues with oil pan which oil pan did you go with