How can I tell if my Tacoma has been re-geared?

Picked up a 2003 Tacoma this weekend. It came with 285s, and since this is my first Tacoma, I have nothing to compare it to. Given the nice modifications on it, I have a feeling it's been re-geared, but since it was a trade in at the dealer, I have no way of knowing for sure.

Is there any easy way to tell if it's been re-geared, and if so, what it was re-geared too?

With the 285s, it seems to have plenty of get-up-and-go, so this has me wondering.

It's a 3.4 with an automatic transmission.

Did a search on this, but couldn't find a "conclusive" thread.

 

@Taco critter

 

mark the driveshaft and count rotations compared to 1 turn of the tire.

Or open the rear and count teeth.

 

What He said ^^^! this has worked for as long as I was alive.

 

This is a very accurate method to determine gear ratio

 

Not really mentioned above - just Jack up one wheel on the axle you are checking and leave the other on the ground.

 

On the surface the previous posts sound logical but "differential action" must be accounted for.
To correctly do this test one must first stipulate the type of diff along with one or both tires off the ground.

1-With an open diff and one tire off the ground, it's DS rotations per two tire rotations due to "differential action".

2-With a locked or limited slip diff it's one tire rotation but both rear tires must be off the ground. No "differential action" occurring.

3-With an open diff and both tires off the ground some means would need to be taken to insure both tires equally turn one revolution (no differential action) and for that matter in the same direction. Double secret super pain in the ass, use #1.