[Excaliber]

I've looked into this myself, considerably cheaper for me as I'm only changing from a top loader to a 5 speed.

TKO600 would be the obvious choice for myself. As mentioned, gear ratio's and the .8 over drive being the primary reasons.

Gear ratio's are INCREDIBLY important to the over all feel of the car. This is an area often comprimised due to cost. Save money somewhere else, get the best ratio's you can afford AND match that cruise rpm to your CAM PROFILE!!! You WILL need to work with a consultant on this. Rear gear ratio, cam profile, final over drive ratio and the all important 1st gear ratio are the primary concerns.

Rule of thumb on gear ratios (by me):
1st through 4th nearly the same as a wide ratio top loader. Over drive, generally .82.