dkpGTCS

Current build is in my signature line though I'm current running a 91 Bama tune from American Muscle. The Mustang is my DD & I don't track/race. I just enjoy having something really fun to drive around in on a daily basis.

Currently have the stock 3.15 gears. Considering 3.55 or 3.73 - I can't see a reason I would go lower or higher. My goal is to get off the line faster without effecting mpg's too much. Top speed isn't a factor since I would never get there anyway.

I've searched & haven't really found info I'm looking for, hence the new thread.

Also, when changing gears what else should be considered being done?

Thanks in advance for any opinions &/or ideas.

AMAlexLazarus

Hey,

Good question and if you're looking to just throw a little pep in her step without completely killing your fuel consumption Ford Racing's 3.55's would be perfect. I've run 3.73's and 4.10's on my Bullitt and depending on how they're driven they can hurt your fuel economy but it was never something that was horrible!

When you're swapping gears it's really important to pick up a Gear Installation kit as well-This is something that we advise customers picking up no matter how new or old their car is. Let me know if you have any other questions and I hope this helps! Shoot me a PM if you don't have our discount code either and I'll get you set up!

Alex

dkpGTCS

Thanks Alex. I have the discount code - in fact you helped me with a very minor issue a week or so ago regarding my wheels/tires I purchased from you guys. Love them BTW - they look great on there now.

I've been leaning towards the 3.55 but since I have a few weeks until I'm back in town I thought I would get some opinions. Thanks for the heads up on the install kit.

JIM5.0

Since our car came with the 3.15:1 rear gear, that means your car is an automatic with the really deep 4.17:1 1st gear.

Going with the 3.55:1 rear gears for improved wheel torque would be best. 3.73:1 would make your 1st gear ratio virtually useless.
Going to 4.10:1 rear gears would be just far too deep of a total 1st gear ratio.

dkpGTCS

Thanks for the technical information - that makes the decision pretty each.

** Hoping AM has some good Black Friday sales on gears... hint hint Alex! :-)

ticopowell

I also think the 3.55 is a good choice... and for black friday I want an airraid cai... lol.

scottmach

None of those gears are a good choice. It's been proven time and time again that gears do little to nothing on these cars with the auto. I've been 11.2 still on my stock 3.15's. A converter is the way to go. Take it from someone that has experience here.

ticopowell

Good point, I guess I was not assuming much drag racing was going on, I think on the street the 3.55 gears would help get off the line a little quicker, but yes for drag racing a new torque converter will get better times. When I raced my auto a new torque converter would have made a big difference in times, but I don't know what difference it would have made on the street.

scottmach

Those gears will not help on the street as well. The car will just be shifting quicker. Again take it from someone with experience.