L86 to L8T in '19 Yukon XL Denali

[L8T BURB]

@L8T BURB, did you upgrade the axle gear, or did you keep 3.08?
Your metro/urban city MpG likely would have been improved by 3.42.

I kept the stock gearing in place. Getting a 10 speed behind that engine would have been amazing too. I am curious to hear more about the driving experience of OP.

 

[Marky Dissod]

@L8T BURB, did you upgrade the axle gear, or did you keep 3.08?
Your metro/urban city MpG likely would have been improved by 3.42.

I kept the stock gearing in place. Getting a 10speed behind that engine would have been amazing too.

Getting a 10L90 behind an L8T, even with 3.08, would've been eye opening, mouth watering, and at times sphincter puckering - but always tragically cool.

 

[L8T BURB]

@chevman88 What grade of fuel are you running in the L8T? It is designed to run 87, and that is what I ran in mine, but I am curious what your stance is on the matter.

 

[Bigburb3500]

Getting a 10L90 behind an L8T, even with 3.08, would've been eye opening, mouth watering, and at times sphincter puckering - but always tragically cool.

If my 6L90 decides to give up… I’ve been messaging with PowertrainSwap about the 10L90 being able to be used. “In theory” it should all work. I am highly curious about OPs driving experience too!

 

[Geotrash]

If my 6L90 decides to give up… I’ve been messaging with PowertrainSwap about the 10L90 being able to be used. “In theory” it should all work. I am highly curious about OPs driving experience too!

I'm with you 100%, but per a few posts up, it seems the bell housing pattern is slightly different on the LT motors vs the LS's that you and I have in our 3500's. I don't believe the 10-speed was ever mated to an LS from the factory.

 

[Bigburb3500]

I'm with you 100%, but per a few posts up, it seems the bell housing pattern is slightly different on the LT motors vs the LS's that you and I have in our 3500's. I don't believe the 10-speed was ever mated to an LS from the factory.

Just because it didn’t come from the factory doesn’t mean it can’t be done! Don’t rain on the parade. The truck really needs 1 more OD gear for non-towing duties on the highway. Would bring up my MPG avg 1-2.

 

[Geotrash]

Just because it didn’t come from the factory doesn’t mean it can’t be done! Don’t rain on the parade. The truck really needs 1 more OD gear for non-towing duties on the highway. Would bring up my MPG avg 1-2.

I agree it would make a great package if it’s possible! I’m also a fan of the venerable 6.0. It’s likely to outlive me!