Its nice to live in El Paso county where we dont have emissions


I would check with whichever company you choose to go with before hunting a 6L90 to make sure their kit can be paired with it and the motor you choose.

As for an 4 speed atlas, way beyond overkill in my opinion. The low 1,2 gear ratios in the 6L80 with an Atlas II is more than enough gearing.

 

There's no debate that the 4 speed case is overkill. It's like going squirrel hunting with a bazooka. But, I'd like to get my overall crawl ratio up around 120:1 or 130:1. I'd do it with the 2 speed case, but the lowest low range offered is a 5:1 ratio. With 4.88's and 1st gear in the 6L80, that only works out to about 98:1. The 4 speeds have 5 different low-low range ratios ranging from 4.08 to 11.70. While still a bit low, the midpoint selection with a low-low ratio of 8.16 works out to about 160:1 crawl ratio. I wished they offered something around 6 or 6.5:1 which would put me in the 120 to 130 range I'm looking for but to no avail, they don't. The other nice thing about the 4 speeds though is that there's enough ratios there to handle everything from highway driving to sand to mud to rock crawling and I don't have to worry about not having enough power or getting too little wheel speed.

FYI, there's a complete LSA out of a 2015 Cadillac with a 6L90 and complete wiring harness on eBay right now for just under $15K. Too bad I don't have the cash and the tranny is a 2WD not 4x4 6L90.

 

doesn't help with the cash part but I know the 6l80 can be converted for 4wd easily and im sure the 90 can also

 

What are you planning to do for axles and tires?

 

Probably going to go with Dynatrac ProRock 60's or something similar. I don't think I can justify the unsprung weight of an 80, even if just for the rear. If I can find a good deal on a KP60 for the front, then I may go that way. Both axles will be locked but haven't gotten to that detail yet. Tire's will be 37's. I'm currently running Kelly TSR Safari's in 315/70/17 and absolutely love them. But unfortunately, this is the biggest size that the TSR comes in. I may go up to 40's but the goal is to still keep the Jeep somewhat low. So even with the 37's, I'll probably trim the rear fenders some in combination with the lift. I've given some thought to adding some helper air-bags for the rear since I intend to build an offroad trailer. But the challenge will be to be able to use the air bags on the highway for stability but still air them down off road and not compromise flex.

 

LSA in JK Build thread REV 2.0 - JKowners.com : Jeep Wrangler JK Forum

 

TOTL - This is sweet but 2 years? Seriously? Sounds like much more here than meets the eye.

 

Vtimer, looks like this will be a very well-thought out JK build. When you are closer to choosing your axles, you may want to read this article:

Comparing Axle Upgrade Options for Your Jeep Wrangler JK, Rubicon, TJ, YJ and XJ Cherokee | Dynatrac Tech Info and News.

It covers the pros and cons of the popular axle choices.