Took a while, but I think I found a solution. Looks like a 411 swap is in my future, because at least one tuning solution (HPTuners) appears to have a setting for doing exactly what I want. https://forum.hptuners.com/showthread.php?37319-ABS-error-from-tire-size-change&p=281353&viewfull=1#po...

I wonder of the PCM does the conversion for the rear sensor so that the ABS doesnt have to know about the gear ratio. I could potentially test that with an oscilloscope on one of the front sensors and the vss out from the PCM.

Does anyone know if the 0411 PCM does it that way?

hmm.. preliminary research suggests that the VSS buffer was only on the 95 and older trucks. http://67-72chevytrucks.com/vboard/showthread.php?t=322002 96 and up apparently the vss just goes to the PCM. Also, per the pinout for the PCM here https://troubleshootmyvehicle.com/gm/4.3L-5.0L-5.7L/pcm-con...

@Antus, I think the reason I believe it needs changed is because the front sensors are on the wheels and the rear is just using the vss in the trans, which is ahead of the rear diff, so if I change the diff, the ratio between the front and rear sensors changes. I dont know if the abs is smart enough...

Also to note, I am a programmer by trade, and have dabbled in some electronics work, and am willing to get into the guts of this thing if need be. If someone has experience taking something like this apart and is willing to give me some direction, I would be all ears

some background: I am building a 96 gmc sierra 2wd into somewhat of an overlanding truck/fun camping vehicle, and two changes I am planning on making are the axle ratio (3.42 -> 4.10) and the tire size (~29 inch to 33). Nowhere I have found has a definitive answer on how I actually change this in bo...