Crossovers

Any problems with swapping a dual thermostat crossover from a 6.5? And what is the heater output thread, 1/2npt or??

Sort of. You will need to modify or replace the throttle cable bracket on the injector pump. There are brackets out there. I think Kennedy Diesel still carries them. Also you will might have a clearance problem with the rad hose going around the alt.
You can use the OEM hose from the civ truck that uses the dual thermostat. The one I had rubbed a bit. IIRC the heater hoes and bypass hose threads were both 1/2NPT. But a reducing bushing from the hardware store will get it done.

Thanks