Yup should be the 80e with the 0.75:1 OD ratio, about 130 rpm difference from the 60/65e/70e trans.

peace
Hog

 

2500 rpms arent bad at all.....im running a 6" with 35's and at 75 im sitting at 2000.I got some 4.55's pretty soon in though.

 

In the GM drivetrain section there is a sticky that has a Calculator for RPMs

Just plug your info in and see if it comes out the same. if it's not right, just adjust the Gear Ratio until it is and that should be the gear you have.

 

Look in the glove box if they have not been changed, gt4 or gt5. I think gt4 is 3.73 and gt5 is 4.1. If they have been changed, jack the truck up, put it in N, and spin the tires one time and count the turns on the driveshaft.

 

4L80 is .78, 4L60 is .67

um......what stoichiometric beat me to sayin. Thats always been the easy way for me to figure out gearing on stuff.

 

yep i agree. spin the tire count how many time the driveshaft turns. One rotation of the tire, if the d.s. turns 3 and 3/4 times your right at a 3.73

 

I have 456 gears and a 60 with 35 inch tires and Im at 2300 at 70. My old truck had 488s and 36s and it was about 2500 at 70. Im with Zippy here, there is somthing wrong here even with a 410 gear he shouldnt have that many R's at 70.

 

80E is .75 and 60E is .70 (or .697 to be exact). The .67 is the 2004R

 

yah i think its definatly not right its not torquey enough to have low gearing ill look into that sticker and rotate the tire but it really is sucking the gas for sure, the part that really gets me is both of my brothers 5.3s can cuise alone beside me at 2000 or under no sweat is that just a tranny difference?

thanks for all the feedback guys

 

Thanks Zippy, you are correct.

peace
Hog