Just ran across the old thread and realized I never updated it. I bought a NOS exhaust manifold and gaskets and was able to fix the exhaust leak. I also decided to try a diesel transmission with OD. At the same time, I realized I had a broken pressure plate so it snowballed into a clutch disc, pressure plate, machined flywheel, rear main seal and oil pan gaskets. I'm not totally sold on the OD trans. It really lugs the engine in 5th unless you are on completely flat ground and first is a little too short but second isnt quite enough when taking off. Its still manageable though. On the first test drive, I saw 65 MPH in 5th gear on the 4 lane while in 5th gear. I can't remember the rpms but the REO was loving it. It's pointless to run that fast but I was in a safe space and figured I'd try it.