difference in differentials?

[Frankenstang65]

Metalhead.....You mentioned that you are planning on doing a tranny swap in the near future and are debating between a top loader 4spd and a T5. The decision you make in this department will have a huge affect on what gears you throw in out back. Since you're going to change the tranny anyways, I'd pop a T5 in there and take full advantage of the overdrive. Having overdrive will allow you a large drop in rpms at higher speeds so that you can put lower gears in the rear. That way you get a more powerfull launch and can still take her on the freeway for a nice easy cruise. The way I see it....it's the best of both worlds.

Hope that helps...sounds like a sweet project...good luck