I assume the question is whether the late or early rear suspension is best as those are the only changes. For a performance application I would definitely go with the later type suspension. They upgraded for a reason. The later type is stronger and gives much positive location. I would also suggest the later, disc type rearend, as it is much stronger than the drum brake type which has a weakness in the taper on the axle where the keyway locates the drum. It does break there in high performance and racing applications.

John
V-performance.com