I have another good friend that is running one behind a 3,400 pound car with a 4 speed as well. If it blows then it blows and I'll go Dana 60. The rearend is not my priority in this list at all, I'd much rather focus my time and effort on the engine because a rearend is far easier to build and swap than an engine but that being said I did ask for all input so I appreciate yours
