Hi friends. I recently swapped a 2.5L NA power plant with a 5.3L Vortec/6L80 in my 1986 D110 Tithonus. We replaced the tcase gearing from 1.667 to 1.222. At the time, we thought the diffs were 3.54. Now, at 70 MPH, the truck runs at 2500 RPM (31.7" tires). I am now thinking I may actually have 4.11 diffs (maybe military used them?)
Can other owners of an LS/6L80 let me know what kind of RPMs they get at 70 MPH? Just for comparison? the 2500 seems a lot.
To reduce the rpms, I could swap the diffs to 3.54 and get RPMs to 2152. Or, I could swap the tcase gears from 1.222 to 1.003 and get 2051. Or heck, i could do both and run 70 MPH at 1767. Not sure if the 315 horses would like that or not but this set up has a lot of power to spare.
But my question is mostly about what other LS swapped people are getting for RPMs at 70 MPH.
Thank you!
Eugene
Can other owners of an LS/6L80 let me know what kind of RPMs they get at 70 MPH? Just for comparison? the 2500 seems a lot.
To reduce the rpms, I could swap the diffs to 3.54 and get RPMs to 2152. Or, I could swap the tcase gears from 1.222 to 1.003 and get 2051. Or heck, i could do both and run 70 MPH at 1767. Not sure if the 315 horses would like that or not but this set up has a lot of power to spare.
But my question is mostly about what other LS swapped people are getting for RPMs at 70 MPH.
Thank you!
Eugene