I have the 2nd gen 12 valve cummins and I'm towing a trailer it pulls fine but going up big hills can be slow I need something that will give her some more ***** but I want to be able to switch it back and forth for towing or something to keep my fule milage where it is I was looking at the mod chips but they only work on the 24v cummins

 

well you cant chip it it is a 12v so bomb it and be done if it is a auto get a tranny built and get gauges and that would be a good start slide your fuel plate tune afc housing

 

with the experiance ive gained from working on locals 12v is you can add alot of fueling upgradeds and actually gain milage if your not pooring the smoke out of it

 

I recommend taking this question down to the 2nd gen area you will probably get better responses down there and you would be able to look around at what others have done to their trucks.