What gears do I have?

[Aaron]

I've been thinking of doing a gear upgrade for a while now and now I'm seriously debating on it. As I was debating on the gear ratio to buy, I started wondering if I already have upgraded gears. How would I know?
So what if a previous owner DID install new gears? How can I tell?
Can I tell by driving a certain MPH in a specific gear, or can I tell by pulling off the differential cover and looking for something?
Any help would be appreciated!

 

[Roland69]

with the rear end up on stands draw a small line with chalk or white out on the drive shaft and spin the rear tire 1 full turn and count the # of turns the D/S makes....ie

3 1/2 turns would be 3:55's
3 3/4 turns would be 3:73's

 

[Foxfan88]

what are your rpms cruising at 65 mph in OD?

 

[dec322]

If you really lucky like me you will draw the line and spin the tire and get 2 3/4 turns from the driveshaft.....my strong and intimidating 2.73s.

 

[Aaron]

with the rear end up on stands draw a small line with chalk or white out on the drive shaft and spin the rear tire 1 full turn and count the # of turns the D/S makes....ie

3 1/2 turns would be 3:55's
3 3/4 turns would be 3:73's

Perfect - thanks!
I'll be ckecking this out this week. I'd better see 2 1/2 to 2 3/4 turns or I'll be pissed!

 

[TomCat]

4.10s for the win!