I have a 4L80E trans hooked up to the vortec. I think I might have to cut out the crossmember. But if that catalog V8 crossmember will work then I think I will just get that. I have a 1999 Isusu NPR HD that I got the motor from and axles. So I can have disk brakes, PS, PB, A/C and so on. The NPR had the same bolt pattern as the GMC. I will be swapping the axles this weekend. Are you running your stock trans?
Make sure you do not use your old wheels with the npr lug nuts. They are a ball seat and your wheels are taper seat. I switched the studs to an American thread so I could use the correct lug nuts.
