Going to use the P30 chassis. Why you may ask? Because I plan on doing things like a front mounted winch, and a rear motorcycle lift which will need sturdy mounts. It also allows strong mounting options for water tanks, and fuel. If you are wondering, the wheelbase on the P30 is 208. The G30 is 154. The final drivetrain will be 6.2 Detroit diesel for its fuel mileage. I'm not going to be racing anyone in a box truck. Turbo 400 transmission, 205 transfer case.
In the front will be a dana 44 already converted to 8 lug. The gear ratio is 3.73. Since the 6.2 does not rev, I'm thinking of using this ratio; I'll have to do some calculations. The tire size is 35". In the rear I have 3 options. I can run whatever the huge thing is on the P30 chassis, but it's 10 lug. The 79 Blazer chassis that is donating the front axle and drivetrain has a 14 bolt full floater. It is also geared 3.73 but it's not as wide as the axle in the G30. That axle is a wide dana 70. The gear ratio is 4.10. I will either re-gear the front, or rear diff so they match at whatever gear ratio works best. Things I have to watch out for are the engine offset in the van body (offset to passenger side by an inch or more, and the steering. The front dana 44 is set with push, pull steering as is the P30 chassis; so that might stay. I have a friend with a forklift, welder, and plasma table who is helping.