LM7 5.3 with 10L80

[CTX-SLPR]

Howdy,

Some friends and I have been discussing the 10L80 swap that's available for the earlier SUVs and Trucks and one of the sticking points is the match between the MPFI 5.3L's (LM7 in my case) and the 10spd, especially considering I have a 3.08 rear end. This is an unlikely solution to my 6L80 woes regardless of the answer as the swap ($2500 for a ~100k mile 10L80 and $3000 for the swap kit) would be ~$1000 more than just getting a reman 6L80 professionally installed ($3000 for the reman, $1100 for the install, $500 for a billet cover TC) but always curious.

Think the combo would be viable as a tow vehicle or it need more rear gear, more low end torque or both to make it work?

 

[Marky Dissod]

Do you plan on keeping your Yukon SLT long enough to recoup ≈$1000 from the MpG improvement?
Although investing in 3.23 (GM OE w/ 10L80) or 3.42 axle (for towing MpG) may be needed for best results.

If you keep the 6L80, 3.73 would be a far better axle gear for towing and city MpG.

 

[CTX-SLPR]

It's more of the practical functionality question vs. what I do specifically.

 

[Marky Dissod]

If you get a 10L80, EVEN GM put 3.23 axle behind it, for good reason.
If you keep the 6L80, 3.73 can't hurt and will only help in terms of improving your vehicle's practical functionalities.