sblair
04-08-2008, 11:03 PM
Hi,
The 6.2L in my '82 C20 is getting tired & moody so I'm wanting to swap it out for a '95 Cummins 6BT and a new transmission with OD (the 6BT turns lower RPMs so I get the impression that OD is gonna be a necessity to avoid changing diff ratios). I like the 4L80E transmission because its got the lockup TC and OD gear and seems to have a better reputation for durability than the Chrysler transmissions. I've also got a US Gear Dual Range OD unit on the floor that is supposed to fit the TH400 I've got on the truck now. So I'm thinking US Gear OD + 4L80E OD = 75mph near the top of the torque curve on the Cummins (around 1800rpm w/3.73 gears and 32" tires) = good mileage! Sorta like "Go large or go home" thinking I guess.
The transmission I found on came out of a '96 2500HD with transfer case. The stinker is that the 4L80E needs a computer. :mad: This would be my first engine/transmission swap, tho I have a guy lined up to help that has done several Cummins swaps before. I'm not sure about his experience with 4L80E's, but I havent been able to find any threads on retrofitting 4L80Es into the '80s vintage trucks. I've heard of 2 or 3 manufacturers of stand-alone TCMs (Powertrain Control Solutions, TCI Auto, and Compushift?). Does anybody have any experience with these units? Or does anybody have any alarming thoughts about using the Dual Range OD unit behind the 4L80E (US Gear seemed to suggest that the TH400 model OD unit should fit the 4L80E) ? The US Gear Dual Range unit already has the electronic pickup wheel for the speedo--even tho my speedo is mechanical. I've seen PCS offers an electronic-to-mechanical adapter box for like $500 but that seems kinda steep pricing? (tho admittedly I havent found any alternatives yet... any help there? :o:). Also, since I'm not sure if the 4L80 came out of a diesel or a gasser, is there anything I should look for on the TC or in a TC upgrade? I'm not planning on doing anything extreme with engine upgrades; just a daily driver that I might do a few "simple" tweaks to bump it up a notch from stock maybe.
Any thoughts or guidance would be greatly appreciated! :rolleyes:
The 6.2L in my '82 C20 is getting tired & moody so I'm wanting to swap it out for a '95 Cummins 6BT and a new transmission with OD (the 6BT turns lower RPMs so I get the impression that OD is gonna be a necessity to avoid changing diff ratios). I like the 4L80E transmission because its got the lockup TC and OD gear and seems to have a better reputation for durability than the Chrysler transmissions. I've also got a US Gear Dual Range OD unit on the floor that is supposed to fit the TH400 I've got on the truck now. So I'm thinking US Gear OD + 4L80E OD = 75mph near the top of the torque curve on the Cummins (around 1800rpm w/3.73 gears and 32" tires) = good mileage! Sorta like "Go large or go home" thinking I guess.
The transmission I found on came out of a '96 2500HD with transfer case. The stinker is that the 4L80E needs a computer. :mad: This would be my first engine/transmission swap, tho I have a guy lined up to help that has done several Cummins swaps before. I'm not sure about his experience with 4L80E's, but I havent been able to find any threads on retrofitting 4L80Es into the '80s vintage trucks. I've heard of 2 or 3 manufacturers of stand-alone TCMs (Powertrain Control Solutions, TCI Auto, and Compushift?). Does anybody have any experience with these units? Or does anybody have any alarming thoughts about using the Dual Range OD unit behind the 4L80E (US Gear seemed to suggest that the TH400 model OD unit should fit the 4L80E) ? The US Gear Dual Range unit already has the electronic pickup wheel for the speedo--even tho my speedo is mechanical. I've seen PCS offers an electronic-to-mechanical adapter box for like $500 but that seems kinda steep pricing? (tho admittedly I havent found any alternatives yet... any help there? :o:). Also, since I'm not sure if the 4L80 came out of a diesel or a gasser, is there anything I should look for on the TC or in a TC upgrade? I'm not planning on doing anything extreme with engine upgrades; just a daily driver that I might do a few "simple" tweaks to bump it up a notch from stock maybe.
Any thoughts or guidance would be greatly appreciated! :rolleyes: