I am thinkin about swaping my M6 with 4.10's out for a Th-350 with 3.73's and a 3500 stall. I am wondering if it will slow my car down or pick it up. Cause i dont want to do all that work just to slow it down.
Thanks Matt

 

If your car is a daily driver, I'd probably keep the six speed. But that's just me. Manual tranny's are a lot more fun, plus you get the benefit of the super-duper-ultra doulble overdrive to slow your rpm's and pick up a few mpg.

If it's drag car only though, and consistency is your thing, I might consider the TH350 swap.

You might have a lot more fun just doing a few engine mods and things, and that way you can still use all of your speedometer.

 

NONSENSE!! Go with the th350, I swapped my 6spd for a th350 and I love it, although I've got 4.10's. Prepare to sacrifice your gas mileage though, even if you go 3.73.