What size gears?

I have a '95 Mustang GT with a T5, and 17" rims, it's completely stock all the way down to the air filter, I bought it, did a tune-up,and added lowering springs, and that has been it thus far, I'm waiting for the O/R X-pipe, and the Shorty Headers, along with trying to find an Explorer Upper and Lower Intake. I've got a set of heads in the sun room waiting to be installed, and I'm trying to decide what gears to go with, but first off, what gears does my car come with? I'm thinking of going with 4.10's, because my plan after i come back from Deployment in May is to start building my 306, it's going to be a 306, with TFS heads, Cam and Intake, hopefully putting out about 350 to the wheels, all N/A, so i figured no power adder, + 306 + 4.10's = good gear ratio.
What do ya'll think? what size gears do i have in the car now, and what would be a good gear ratio to go with when i purchase them?
 
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I've ran 3.73 and love them, although I wish that I'd went with 3.90. I've never ran 4.10, but think that may be a bit much, but perhaps not...

I think that most (not all) came with 3.08 stock. As mentioned, the axle code will tell you what came stock. It is always possible that one of the previous owners may have already changed the gears. To check, jack up the rear. Note or mark the position (rotation angle) of the driveshaft. Then turn the rear wheels one complete revolution, counting the number of times that the driveshaft rotates. Make sure that both rear wheels turn the same direction together the same amount. They should unless your posi (clutch packs) are shot. If the driveshaft turns a bit more than 3 times, then you've got 3.08's. If it turns 3 3/4 times, then 3.73's, etc.

Rick
 
That was the other common stock ratio. Obviously, the lower you are now, the more benefit you'll see from gears.

FWIW - gears should be first on your list of performance upgrades. They have the best cost-to-performance (sorta like cost per HP) ratio.

Rick
 
Yeah we need the axle code, or there might still be a thin stamped piece of metal on the diff that says the gear ratio. It's either 2.73, 3.08, or 3.27(rare).

And definately go w/ 4.10's, I wish I did.
Scott
 
i had a Silver '99 V6 about 2 years ago, that i used to play around with, i blew up the stock 7.5 rear, so i replaced it with an 8.8 and 3.73's... I ended up selling it, and there was a huge controversy over whether or not i I had Gas on the car... I'll never tell either way, but the point is, I didn't like the 3.73's I didn't feel a BIG difference, a little one, yes, a big one.... No, thats why i was leaning more towards the 4.10's or as someone else stated, maybe even 3.90's. the exhuast and gears are my first items to replace, the 306 will be built when i come home from deployment.