Quote:
Originally Posted by Average Joe
Thanks for the bump Mr CG. 
Ooooof! It’s been a year. Lots of life changes and other projects have held up progress on the Burb. I have been collecting parts and pieces for a drivetrain upgrade though. No, I’m not doing an LS swap!  I’ve got another 454 which will be rebuilt with a lil more squeeze, tiny Comp Cams roller, some reworked peanut ports, and a set of small tube headers. I’m still on the hunt for a noisy gear drive. Yeah, I’m that guy. lol. I’m currently running an AFB style carb but have a few qjets I’d like to try.
Backing that will be a new to me 4L80e I recently picked up. I’m researching controllers now. Looks like US Shift offers the best bang for the buck.
I’m determined to up my mpg. It’s not horrible now at just under 14mpg Hwy but I’d like to see that up around 17. I think I’ll have enough off idle torque to make it a reality. Cruise RPM should come in around 1500. I may have to go to a 3.42 gear but I’m hoping to retain the 3.07’s.
Here’s a few pics from the last year. |
I can just about bet the 3.07's will be to high. It may be fine until it shifts into OD and the lockup kicks in. My experience was that when that happened the transmission would overheat and blow fluid out of the front seal. If I drove it locked in 3rd it was fine. Mine was a 4l60e but I'm pretty sure the results would be the same. Maybe the 4l80 would take more heat. I installed a 3.73 (because I had one) and it worked great and gets right around 20mpg. Engine is LS1 5.7. The 3.42 may work fine though.
Good luck whatever you decide to do.