Another 37 vs 40 thread

Basscat

Basscat

Member
Which LS3? 5.3?, 6.0? Or 6.2? 40s, including a spare, along with heavier wheels and the heavier axles will rob a bit of power from the V8. Much of that due to shear rolling resistance. You can feel the difference between 37s and 40s. Assume you’re at relatively low altitude as that can rob even more of that V8 “snappiness”. If you like to whip around and do burnouts the 37s will be more fun. If you like rolling over a lot of stuff while wheeling you’ll like the 40s.


Sent from my iPad using WAYALIFE mobile app
 
Irish JK

Irish JK

Caught the Bug
jdofmemi said:
That would be like going back to stock, except nearly unbreakable.

Sounds like a good challenge to pick your lines.
Click to expand...

Less clearance.


Basscat said:
Which LS3? 5.3?, 6.0? Or 6.2? 40s, including a spare, along with heavier wheels and the heavier axles will rob a bit of power from the V8. Much of that due to shear rolling resistance. You can feel the difference between 37s and 40s. Assume you’re at relatively low altitude as that can rob even more of that V8 “snappiness”. If you like to whip around and do burnouts the 37s will be more fun. If you like rolling over a lot of stuff while wheeling you’ll like the 40s.


Sent from my iPad using WAYALIFE mobile app
Click to expand...

LS3 is a 6.2. 40s are liveable with a 3.6 Pentastar. With more than double the power, it’s plenty fine.


Sent from my iPhone using WAYALIFE mobile app
 
Brute

Brute

Hooked
You just pick the harder lines...all the time. Then you start thinking you can defy gravity, then do something stupid...
 
TheGrendel

TheGrendel

Active Member
nothing wrong with rolling 37s. eddie ran 37s on one of his rides for a long, long time. is this daily driven? me personally. i've got short legs. i am on 35s right now and will eventually go to 37s. but, i wouldn't want to have to get in and out of 40s if i was daily driving.
 
SLO

SLO

Member
To answer a few questions. The LS is actually a L94 which is a truck motor similar in specs to the LS3. 6.2L with 408HP w/o modifications. Another thing to note is that I would be going from 37” Nittos that weigh 86 lbs each to 40” Coopers that weight 92 lbs each. 6lbs per corner shouldn’t be as drastic as if I were going from 37” Nittos to 40” Nittos (almost a 20lb jump).

This is not a daily driver and I’m 6’ 2” so not worried about getting in and out. The question about where and who I wheel with is a great question. I’m Oregon and mostly wheeling in the Tillamook State Forest but we do annual trips to Rubicon, Moab, etc. Most of the guys are on 37’s but most have also talked about jumping to 40’s. I’d love to have 40’s for the Rubicon but i have heard a few people say they prefer Moab on 37’s.
 
Last edited:
TheGrendel

TheGrendel

Active Member
SLO said:
To answer a few questions. The LS is actually a L94 which is a truck motor similar in specs to the LS3. 6.2L with 408HP w/o modifications. Another thing to note is that I would be going from 37” Nittos that weigh 86 lbs each to 40” Coopers that weight 92 lbs each. 6lbs per corner shouldn’t be as drastic as if I were going from 37” Nittos to 40” Nittos (almost a 20lb jump).

This is not a daily driver and I’m 6’ 2” so not worried about getting in and out. The question about where and who I wheel with is a great question. I’m Oregon and mostly wheeling in the Tillamook State Forest but we do annual trips to Rubicon, Moab, etc. Most of the guys are on 37’s but most have also talked about jumping to 40’s. I’d love to have 40’s for the Rubicon but i have heard a few people say they prefer Moab on 37’s.
Click to expand...

this is easy in your situation. go 40s and don't look back.
 
Basscat

Basscat

Member
Most folks who think about 40s and have 37s won’t stop contemplating until they have 40s. Then they either stay with them or go smaller again. You won’t shake that bug until you go 40s. Then you’ll know for sure.


Sent from my iPad using WAYALIFE mobile app
 
SLO

SLO

Member
Basscat said:
Most folks who think about 40s and have 37s won’t stop contemplating until they have 40s. Then they either stay with them or go smaller again. You won’t shake that bug until you go 40s. Then you’ll know for sure.


Sent from my iPad using WAYALIFE mobile app
Click to expand...

Solid advise! I think you pretty much nailed it. Maybe I’ll hold off on selling the 37’s for a bit.


Sent from my iPhone using WAYALIFE mobile app
 
R

Rocralr

Member
Hello all. I just picked up my JKU from Motech. I had an L99 crate engine put in along with a crate 6L80 transmission and a new Atlas transfer case. I am running 40'S on Currie RockJock VXR 60's and it drives great!!! +++ a lot more. Robbie at Motech is the way to go.
 
fiend

fiend

Caught the Bug
Rocralr said:
Hello all. I just picked up my JKU from Motech. I had an L99 crate engine put in along with a crate 6L80 transmission and a new Atlas transfer case. I am running 40'S on Currie RockJock VXR 60's and it drives great!!! +++ a lot more. Robbie at Motech is the way to go.
Click to expand...

CA emissions legal?


Sent from my iPhone using WAYALIFE mobile app
 
Exodus 4x4

Exodus 4x4

New member
fiend said:
Possible. L99 is the Camaro engine, so you’d meet the GVWR limitation.


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

The classifications between car and truck are beyond stupid considering the block and head is the same. Robbie is pretty careful about what he does in regards to compliance so I’m sure it’ll meet emissions.

I personally don’t offer the car engines because they’re more expensive and there isn’t any power gain.


Sent from my iPhone using WAYALIFE mobile app
 
zimm

zimm

Caught the Bug
Rocralr said:
Hello all. I just picked up my JKU from Motech. I had an L99 crate engine put in along with a crate 6L80 transmission and a new Atlas transfer case. I am running 40'S on Currie RockJock VXR 60's and it drives great!!! +++ a lot more. Robbie at Motech is the way to go.
Click to expand...

How much does that cost? $20k? I want a V8 someday.
 
SLO

SLO

Member
Rocralr said:
Hello all. I just picked up my JKU from Motech. I had an L99 crate engine put in along with a crate 6L80 transmission and a new Atlas transfer case. I am running 40'S on Currie RockJock VXR 60's and it drives great!!! +++ a lot more. Robbie at Motech is the way to go.
Click to expand...

When did you drop it off? Curious if mine is close. What color is yours? I’m sure I saw it there when I dropped mine off?


Sent from my iPhone using WAYALIFE mobile app
 
You must log in or register to reply here.
Top Bottom