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i was wondering if any one could help me find out what gear i have. i have a tremec t-5 wit the 2.95 first gar. at 75miles an hour i am pulling 2ooo rpms almost
 

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Well I guess I dont understand what you are asking. Are you asking what differntial gear ratio assuming you have a superduty T-5(that tremec didnt make). You need tire diameter to tell, with what gear(5th i assume) at 75 and 2000rpm.
 

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what is the 5th gear ratio and tire size?
with a 26" tire and .68 5th gear :

2.73 gears 75mph --> 1799 rpm
3.08 gears 75mph --> 2030 rpm
3.27 gears 75mph --> 2155 rpm

i have an excel spreadsheet that does all the calculations for you if you want me to email it to ya. let me know.
 

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stock tire is 25.7"...superduty T-5 is .63 which means you would have a 3.23, based on 2000 rpm.....its a 3.08, the tach is just under 2000 as you said
 

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25.7" tire, .63 5th gear 75mph:

3.08 -> 1903
3.27 -> 2020
 

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in that case....

3.08 --> 1908 rpm
3.27 --> 2026 rpm
 

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Kermita, TREMEC now makes all T5's ( they bought out the BW tranny department .) You might have 3.55's in the rear. At 75 with my stock T5 and 3.08's my car was just at 2,000 rpm, my friend who has 3.55's and the new Z spec T5 is at the same rpm as me at 75. We both have the same 245/50/60 tires on our cars so that wont play into effect. So if you do have the new Z spec tranny you could have 3.55-3.73's in the rear. Best way to be sure is to jack the rearend up, mark a place on the driveshaft to a referance place, rotate the tire around 1 complete turn and count how many times your driveshaft turned around according to the referance point. 3 1/2 turns would be 3.55's, 3 turns will be 3.08's, you should get the point by now. Shouldnt take you but 5 mintues to be 100% sure of what you have instead of guessing like we are.
 
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