Got new Interstate batteries today, and it's kinda like having new headlights they are so much brighter. Also the truck seems to run a little smoother. I went with a group 24 instead of a 27 that these take, or 31 that takes modification to the box's. They gave me a little more and less, Got 800 CCA over 750 CCA of the 27's but lost 10 min. in reserve (135 for 27's and 125 for 24's), but I can deal with that. And they were both the same price, out the door was $240 and change, with tax and all. About $113 pre-tax.

Just thought I would let yall know of other batteries that will work in these and give ya same or more juice.

 

I've found that old batteries that just don't do it anymore for a Cummins will work fine for other vehicles.
I have several that have been powering a couple tractors, gassers and other equipment for several years.
Better than the five bucks they give for the old ones at the autoparts.

 

The PO put 31's in & they did not need to modify the box just set the bat's on a piece of 1x6.

 

and you haven't had a problem with the batteries not charging when it gets real cold?
My experence is the bottom of the battery has to be in contact with the temp sensor or the PCM thinks the battery is frozen and won't charge.

 

Bill they haven't missed a like till a couple of weeks ago & now they are fine again after putting post shims on so the clamps get good contact. Had 'em tested last month show good & 108 amps charge at idle.