Allison convertor

Im running an Allison AT 545 behind a 12 valve in my dually, allison offers 2 convertors a gas and a diesel, do you have any idea how much the rpm's differ between the two? The diesel is a 1.72:1 the gas is a 1.96:1, any help would be greatly appreciated not many options for these old Alisons.

The gasser will be way too loose. Stick with the diesel one. I can work on the fluid coupling for it if need be.

That's what I figured, ill give u a call sometime to discuss my options thank you.