here is my situation. I currently have a 4:57 gear in a 9" ford behind a t400 trans w/brake and 5000 stall. I have a 13:1 377 . I am going to replace the t400 with a 4 speed (no more racing) I just want to drive my car now. If I go with a 4 speed with the deep 1st gear (2:52 i think , correct me if I am wrong) what would be a good gear to run. I was thinking 3:89 but maybe a 3:70 or higher would be better. I have no intention of changing anything engine wise any time soon. oh ya, cam specs are duration 266/274 @.050 and lift is .570/.590 solid lifter cam (not roller)

3.89:1 is my vote. Nice launch on yours.

The 3.89:1 has my vote too with an M22W (2.56:1 1st) Muncie gearset. A very fun combination.

Going from a 4.57:1 to a 3.89:1 differential will feel like you installed an overdrive transmission!