Trying to decide on an atlas and i am leaning toward the 3.0 highlander. AA says it is slightly stronger and it will be bolted to an NP435/chevy 350, Rockwell axles. WIth the 6.72 gears in the RW's i think 3.0 in the tcase will be plenty low enough. Opinions?

Also which side would be suggested to run with this setup, Drivers or passengers since i can setup the front rockwell either way. The rear axle is a non-steer axle.

Jim

I would go drivers side as if you ever plan to sell it it will go fast to YJ/TJ guys. :beer:

The Highlander would be a good way to go. I have heard Rockwell guys complaining about the lack of throttle responce with the super low axle gearing.
The 3.0:1 gearing is slightly stronger than the lower geared units as well, due to the drive gear being larger, but I think this is not a magor issue.

4:1 but that is my opinion and you know what they are like:flipoff2:

It really depends on what you intend to use the rig for...if it's all around wheeling or anything that involves mud or sand where u need wheelspin, definitly the 3.0. If you're gonna be competing, I'd look towards the 3.8. If you're only cruising monster boulder fields, then 4.3.

ditto RedBullJeep, i run a NP205 and rockwells, with a SM465, and it's nowhere near low enough for serious rocks. I can stall it easily. so, with 3:1 in the case, i would still be too high. Eventually, i'll run a Klune-V...

Throttle response is slow in first. Yes it is! That is good! I plan to ride in 2nd (auto manual valve body) and for downhill (compression braking), tricky spots<need to go real slow> use first. I believe riding in second gives you a chance to use all three gears off road. Most people only use first, and when their gettin it up shift to second but rarely use third. I chose the 3.8 with a turbo 400 and 6.72 rockwells, 44s, 454. I think the 4.3 is too low. and I just couldnt buy a 3.0.

I ran the numbers for about 5 days before I ordered. I knew what wheel speed/ crawl ratio I liked and just tried to match it.

I have found this http://www.s-series.org/htm/calc/crawlratio.htm
to be the best way to figure this out.
But you need some experience (seat time) with familiar ratios,tire dia,motor trans to compair.

Good luck,
Dan

P.S. I still havent had a chance to drive this combo but should have it done soon.

Thanks for the help everyone.

Being on the east coast it will see a lot of mud as well as rocks but using 2nd and 3rd is a viable option.

it appears that the 3.0 yeilds a 134 crawl ratio and the 3.8 a 174 if i didn't mess it up. The 3.8 would probably sell easier if i ever did put it for sale.

But with my previous setup 4.0L,NP231,AX-15,4.56's and 38's i was already in 2nd in the mud so I am doubting 2nd would work with the new setup i would probably have to go to 2nd in 4hi????

Originally posted by elf_cruiser
I can stall it easily.

How can you do that with that 120hp the 2F puts out??:flipoff2: :p

:flipoff2: McGoo

It's 130 hp... jeez!

Originally posted by liquidkool
Being on the east coast it will see a lot of mud as well as rocks but using 2nd and 3rd is a viable option.



Rockwells + standard shift + mud? :eek:


TEX

Originally posted by elf_cruiser
:flipoff2: McGoo

It's 130 hp... jeez!

hey, at least its EFI...that must tack on another 5 or 6! :flipoff2: LOL