Getting back on topic, one thing about the 4l80 transmission that I do not like is the ratio in 2nd gear. I have two 3/4 ton suburbans. One is an 86 454 THM 400 w/3:73 rear ratio. The other is a 2001 6liter 4L80 w/4:10 rear ratio. The 86 actually has a little taller tire that reduces the effect of the ratio some. I have a vintage 31' Airstream trailer. There is no doubt that the 2001 would pull faster and probably win a drag from the stop light, but when you try crossing independence pass, the 454 truck will March up in 2nd gear at 45 MPH., without feeling like you are thrashing it. With the 6l truck, I have to run in 1st gear at 25- 30. The ratio in 2nd gear is too tall even with the lower final drive. The 454 makes torque, the 6l makes horsepower. (There is a photo of my 86 in the new gallery section.)
Just something to think about.
Steve
Last edited by 20Mercman; 02/28/2021 11:17 PM.
