6.5 L TD Hummer H1 Modifications

Hey there,

I am just starting to modify my truck (2000 H1) and was looking for some advice on engine modifications.

Have a stage 4 predator motorports package currently in it (PCU, HO Injectors, HO fuel lifter pump, HP wastegate controller, exhaust, pmd isolator, etc).

Was wondering about possible propane or water or water/methanol injection to go with it? Maybe a dual turbo setup (although I the space under my hood in running very low)?

Does anyone know of if this is worth it and what the best option/kit would be? Does it have to go in the bed if it is propane or can it be mounted under the rails like the fuel tanks on the other side? Any other options for getting around 25/30 MPG (other big diesel trucks get this mileage or better)

thanks for your help and hope to get alot of thoughts...