The motor is the basic "N" series 3-banger, supercharged and making about 105 Hp at a little over 200 ft/lb torque. A regular Spicer 3053A from a multifuel duece, stock transfer, stock gearing, 42" Goat tires & wheels. It is a very tractable combination in an M37, as I have a bit over 250,000 miles on it now with little more than normal maintenance on the engine since 1975. I have run thru 1 transfer, several ring & pinion sets, and a few axle shafts and U-joints. 5 sets of brake shoes, and a pile of tires in that time. Max velocity is 68 mph, and it will cruise at 65 on the flat giving about 18 miles/gallon hwy.
I have power braking with the air-pak from a duece, with a full air system on board. It usually pulls a 105 trailer with brakes making that a lot safer than a 101.
An extra tank allows 80 gallons of Diesel on board, and it will always go at least 1,000 miles on that. I always wear earplugs when running on the highway, but it isn't any noisier than a 5-ton at full tilt.
As far as the conversion using a 6.2, I have no experience with that. I feel the 150 hp would be agreat thing, and it ought to fit OK. The biggest bugaboo with any repower of a G741 is the lack of real estate for engines of size.
dg