my old chevy had a 14 bolt d-44 combo. i ran 39.5 tsl swampers pushed by a 454 bb. they were both open diffs. even with a heavy foot the only trouble i had (that really wasn't trouble) were the axle tubes started to pull out of the pumpkin. i think that had more to do with the crapo lift i ran than anything else. huge soa blocks. with so much wrap on off camber situations the spring twist worked the tubes out. i've been considering putting those axles under my jeep for a while, bt i've heard that a bit of ground clearance is lost with the 14 bolt. the 14 bolt has a huge pinion and brakes, and is nearly indestructable.