love my 4.10's in my 6 speed

 

i just remember doing 373 in my mustang.... i always regretted not doing 4.10s or 4.30s. im @ 4.10 now in the TA, and i havent driven it enough since the swap to really have an opinion, but if its a race car then bigger is better.... keeping in mind the warning i gave above. its all about when u max out your drive gears. highway pulls suck when you go into OD at 95mph

 

so whats the highest you should go with in an auto car ?

 

a guy a work with have a 97 z with an auto put in 4:11's and just like specter said, he said it pulled way hard if he floored in on the freeway, he ended up selling the car then bought a manual. he put 4:11's in that and he said it was amazing the difference the manual made with the gear set up. Can't wait to put go from 3:53's to 4:11's in my car.

 

hmm, does anyone know how to figure out what top speed for each gear would be for different gear ratios? maybe 4.30's would be better.

 

i usually just good search for a top speed calculator like this one
http://www.csgnetwork.com/rearendgearcalc.html

 

3.73..

 

It all depends on what transmission you have. The reasons anything larger than 3.73 in an auto is too high:

1. The 4L60E has some VERY high gear ratios in its gear box. First gear is something like 3.1 while in a T5/T56 it's 2.2/2.6 respectively. Or something close to that. You'd end up maxing out 3rd (in an auto) at like 70 mph.

2. That being said... The overdrive gear in an auto would murder your mileage so it wouldn't be ideal to use on the street.


At least that's what I think... Thus going into OD at 70 mph would put you at 3 grand and higher on the highway lol... Meaning you get like 10 mpg :P