JS alternator: shorter belt or larger idlers?

[TRMFAM]

I have a 2004 LJ with AC and purchased the upgraded Jeep cables and the JS alternator. The alternator pulley is smaller in order to turn faster and produce more amps at lower rpm (idle) but they instruct you to purchase a 1/2” smaller belt or larger idler pulleys.

Has anyone already done this? I am struggling to find a 1/2” shorter belt listed.

JS Alternator

Hoping someone has already worked through this.

Thank you for your help!

 

[TRMFAM]

Ahh reading more on the JS site they state 1/2” - 1” shorter.

The stock belt is a

K060882​

Effective length of 88.3” 6 rib 20mm width

I see Gates offers

K060874A​

Effective length of 87.44” 6 rib 20mm width

I think that is as good as it gets…anyone else go a different route?

 

[Ashim]

That's what I would recommend.

 

[TRMFAM]

Edit I found another belt not listed in the all parts list at gates and it is:
K060876 6 rib 20mm
87.57”

So it is closer to middle of the range and it is half the price of K960874A

 

[MikeE024]

Edit I found another belt not listed in the all parts list at gates and it is:
K060876 6 rib 20mm
87.57”

So it is closer to middle of the range and it is half the price of K960874A

When I changed up my setup, I purchased two different sizes and test fit them both. The size I initially preferred ended up being a little too loose once broken in.

I’d go with the smaller option if you can get it on without much fuss.