gears...
 

a quick question, apparently richmond doesnt make 3.55 gears for the 7.5 rear, does any company make 3.55's for a 7.5 rear or should i just go for the 3.73's? i have a 350 5-speed mostly going to be used for summertime, a lot of shore trips, so highway will be my concern

3.73s shouldn't be too bad on the highway. Just :google: an online calculator and enter in your gear, speed, tire height, and 5th gear ratio. That will give you the RPM that you will cruise at.

- Justin

well i figure it to be about 2500 maybe? sound right at all?

At what speed? 2500ish at 75ish will prolly be about right. I don't know what ratio 5th gear in a 3rd gen T5 is though....

- Justin

probably .63 for 5th gear

Tim says it's a .67:1

- Justin

well being as it is, about 2200 at 65 mph ?

With 3.73s:

2100 @ 65 mph
2425 @ 75 mph

With 4.10s:

2300 @ 65 mph
2660 @ 75 mph

I say go with 4.10s :drive:

- Justin

thanks for the help, i think i might just go with 3.73's or maybe the 4.10's ... i dont know, only time will tell :scratch:

4.10s FTW!!!

- Justin

:werd:

On my 87 monte SS with 3.73s, i was running right around 2700rpms at 80mph and im running a 255/50-17 rear tire.

That's on a 27" tall tire though....

- Justin

i would go with 3:73s for the follow:

3:73s were the performance option gear for the T5 trans. They work great with the low ratios of 1st and 2nd and still give you good milage in 5th.

In your other post you were talking about traction problems. 3:73 will add to your problems, but 4:10s would be even more of a problem.

Depending on your exhaust, 4:10 are going to push your RPMs up when cruising. I had headers and a flowmaster and the drone @ 75 MPH was too much for me on long hauls.

my .02

JB

If you've got a motor that can rev, 4.10s with a T5 will be OK. I know in my Monte (TPI 305/T5/3.73s) it'll wind out 1st gear pretty quick, especially since the motor is done at 5K rpms. Choose wisely.

would this be around the same for my car or completely different? i think i have 235s, a4

The rev's would be just a touch higher for your car, since the A4 OD is .70:1, compared to his .67:1

It would be less than 100 RPM difference though, your tires should be about the same height, 25.6"-26.1" tall was standard size for every 82-02 F-Body.

- Justin

4.10s

no love for the 4.56's...I see how it is... :lol:

his screen name looks alot like mine!! haha cool :)

ill see first hand what 4.10s can do and what the rpms will be when kasey gets his installed and ill see how i like it