I've twisted a few Class 8 driveshafts in my day. Cats are noted for tremendous torque rise and one has to be careful about letting out the clutch, loaded on a hill. I dropped an intermediate driveshaft (between the transmission and front drive in a dock in Detroit and the truck never moved. The driveshaft (which is substantially larger than a pickup truck driveshaft, twisted like a soda straw.
I keep my diesel pickup truck basically stock. I follow Riff Raff diesel owners advice and I don't fool with timing or timing chips. I've increased the breathing capabilities (intake) exhausting efficiency (straight pipe from the turbo back, bolted on a quicker spool up turbo housing (Banks Quick turbo) and deleted all the emissions stuff. Mine pulls strong through a Ford SVO modified and built E4OD with a huge transmission cooler and deep sump (increases the fluid capacity by a gallon) pan.
I have no desire to build a hot rod, just want a reliable diesel engine and my 97 7.3 Navistar is just that. 7 more years and the truck qualifies for historical plates and I plan on owning it then, just like now.
