Looked and looked and looked and found nothing. I am in the planning stages of a 93 4wd s10 blazer swap and would like a 6l90e 4wd trans for the extra gears but I see nothing about that combo. Looking to do a simple 400 chp build on the l33 (already have it) with worked 243 heads and a ported/polished truck intake and TB. This truck is going to be a hwy truck/ tornado chase rig, so squeezing what ever mileage I can out of it would be great, but not end all be all. I have a 4l80 but if a 6l80/90 will give me a couple mpg bump it might be worth looking into more heavily. So any info that would be helpful would be great. Thanks in advance.

 

The 6l80/90 will only work with gen4 58x motors using same year pcm. I have one in my truck and all that was needed was some repining of the harnes but if you can get you a 5.3/6l80 harness it should all be plug and play. Speartech i believe has a controller for the 6L trans now i think.