New Gears..3:73 vs. 4:11

**joliver2** · 10-12-2008, 06:35 PM

Kinda curious as to which gear ratio that you guys prefer. My car is a daily driver so I dont want my mpg to drop tremendously. My car has bolt on mods but nothing major and I dont really go to the track, just want a little more bottom end. So here are my questions.

How many mpg am I going to lose with 3:73 and 4:11?

What are some good gears other than Richmond, SLP, and Auburn?

What am I looking to pay for the gears and to have them installed?

**JoshieDoom** · 10-12-2008, 07:43 PM

Lot of local KY guys use Motive, but they always end up blowing up the 10bolt and go for 9 inch or the 12 bolt. Give horsepower house a call. They are in bowling green.

**Tyler_LS1** · 10-12-2008, 07:51 PM

Motive makes great gears, i have their 3.90s and love em

its been a while but i think i paid 3xx to have them installed maybe 400 id have to look

**joliver2** · 10-12-2008, 07:53 PM

Originally Posted by JoshieDoom

Lot of local KY guys use Motive, but they always end up blowing up the 10bolt and go for 9 inch or the 12 bolt. Give horsepower house a call. They are in bowling green.

I dont completely understand the whole "bolt" thing. What are our cars stock? I was thinking that they're 7.5 inch.

**Tyler_LS1** · 10-12-2008, 07:56 PM

Originally Posted by joliver2

I dont completely understand the whole "bolt" thing. What are our cars stock? I was thinking that they're 7.5 inch.

Our gears are 7.5 inch The housing is a 10 bolt. the ford 9 inch has a 9 inch gear

**JoshieDoom** · 10-12-2008, 07:57 PM

How much HP are you laying down?

**joliver2** · 10-12-2008, 08:02 PM

Originally Posted by JoshieDoom

How much HP are you laying down?

I'm probably putting down like 400 at the crank. So I can order 3:73 gears that are 9 inch and 12 bolt (rather than 7.5 inch and 10 bolt which is stock) and it bolt up fine? Or in order to do that do I have to do a complete rear end swap?

**Tyler_LS1** · 10-12-2008, 08:05 PM

you have to do a complete rear end swap to a 12 bolt or a 9 inch

**joliver2** · 10-12-2008, 08:08 PM

Originally Posted by Tyler_LS1

you have to do a complete rear end swap to a 12 bolt or a 9 inch

Ok, that whats I thought. I know im looking at big money to do that so roughly how much?

**Tyler_LS1** · 10-12-2008, 08:19 PM

Originally Posted by joliver2

Ok, that whats I thought. I know im looking at big money to do that so roughly how much?

depends on what you get,

Moser 12 bolt from Texas Speed will run you $2150

Moser 9 inch from Texas Speed will run you $2250

That was just one site i looked at, the prices vary elsewhere.

**joliver2** · 10-12-2008, 08:28 PM

Originally Posted by Tyler_LS1

Motive makes great gears, i have their 3.90s and love em

its been a while but i think i paid 3xx to have them installed maybe 400 id have to look

When you jumped up to 3:90s did you notice a big change in your gas mileage..I dont drive a whole lot of interstate. Mostly around town or back country roads running 55-60