I actually just got off the phone with the shop i am swapping from stock 8.8 gears to either 3.73 or 4.10 posi unit. the trans is a t5 wide 3.31 first and .68 final Motor is 5,0 e303 gt40 heads 670 holley, 26in tire diameter 17s nitto nt555r 275 40 street slicks will see highway when wife and I go to the beach or i take it to work 32.5miles of interstate. Question is which gear with the information given.
Like said, 3.73s (3.73 x .68= 2.53) As a side note, I run 4.10s with a 3.35 T-5 on my Cougar and although a useless combination, it's a LOT of fun on the street and really quite acceptable on the hi-way .....just a couple of hundred RPMs more.
Thanks while I am in there I am rebuilding the trak loc and bearings. I just don't want to regret not getting the 4.10
I have 4.33 and 4.11 ratios to chose from so my plan is to sell both and buy some 3.50's. I love the 4.10 ratio for the brutal acceleration but my last car that had them had no overdrive and a very loose converter. The five speed with an OD will be nice but with first so deep I might as well take advantage of it.
