I have seen some people have put in 4.10 gears. I have also recently seen 4.30 gears. I have a manual tranny and was wondering:

Since they are similar in price, why are 4.10s more popular than 4.30s? (At least I have heard more about 4.10s than 4.30s)

Has any one installed 4.30s?

What is involved in installing gears? Is it recommend to have a shop install them, or is it something a person can do at home?

 

I've thought about 4.30s myself. Mileage and acceleration will not vary considerably from 4.10s. For example, you'll redline 1st at 36.2 mph with 4.10s, 34.5 with 4.30s (@6000 rpm). Really seems like a toss up. You'll get slightly higher tq multiplication with 4.30s but like I said you probably won't notice a difference. FYI, gear calculator here. The spacing on the 3550 is pretty close to the 3650, so the numbers should be close.

As for a self-install, DON'T DO IT, unless you've got serious mechanical skills. Find a shop.

my .02

 

do not install gears yourself as stated....and it comes down to gas milage...if you dont care much about it but you want that off the line grunt 4.30s are great but if you wanna save a lil money on gas go for 4.10s i would go for the 4.30s myself

 

I'm stuck on deciding between the two ratios as well. In the 2004 and earlier 2 valves, it was 4.10's for street/track and 4.30's for the hard core weekend warrior. Taking into account the different wheel diameter of the '05, 4.30's actually end up being about 4.20's, and 4.10's end up being about 4.00's as compared to the previous mustangs.

Many of the previous model years wished they put in 4.30's, so part of me is really leaning towards 4.30's since it falls right between. That, and our 3 valve engine breathes easier up top, which is even more of a reason to not fear the gear!

I have a few months to decide... :scratch: