88mustangATL

i have an 88GT with 3.77 gears in it. I like the acceleration of the gears, but at times I hate the lack of really being able to cruise in 5th gear.

Would there be a noticeable difference if it I went to the 3.55's ?

mjr46

3.77's?? or 3.73's?? either way unless you are running a small tire 3.73's cruise just fine on the highway.....mine at 65 pulls about 2300 rpm's

luckythirteen13

the rpm difference between 3.73 and 3.55 at 4000rpm is less then 200rpm. that means at crusing, 2500ish, there is closer to 100rpm difference. your stock tach isnt even accurate enough to show the difference. dont waste your time or money making the switch

Timspony

Not worth changing IMO!

w8less

dont waste the money especially since its so hard to come by anymore

Portmaster

Did you have the gears installed or did someone tell you thats what they were. You should be able to run 90 down and interstate with no problem. Pull the cover off the rear and count the teeth in the ring gear ( the big one) then count the teeth on the pinion gear (the small one that drives it) and then devide the number of pinion gear teeth into the ring gear.

example: Ring gear 41 teeth, Pinion teeth 10= 4.10
Ring gear 41 teeth Pinion teeth 11= 3.73
And so on.

You might open it up to discover you have 4:56's. The it would be worth the swap

w8less

or he could jack the rear up, mark the driveshaft and spin the tires. however many times the driveshaft spins for one revolution of the tire is what gears he has

Portmaster

Not accurate unless the car has a spool

wowvfast

it's close enough if you use the right tire

I like my 3.55's in my 5 speed car makes 1st so much more useful but, no way in hell would I go thur all that to make the change if .73's are in the car unless maybe if I was adding a supercharger

Portmaster

I've seen a lot of people make that mistake only to be off .50 or more. Assumption os the mother of all F-ups