Hey guys, spent some time searching around and didn't find anything referencing the heads specifically, so here's the deal:

I have a 2000 4wd blazer with a bent valve caused by the rocker breaking. I recently bought this from someone and haven't had the chance to fully check out the head yet, but hoping a new valve and rocker are all I need to get it back on the road.

Meanwhile, I have a lead on a 2001 and 1997 4wd blazers with transmission issues but strong running engines (in theory)

My question is: How different, if at all, are the cylinder heads between the years 96-2002. I seem to recall at some point a sensor was changed in the head, but anything beyond that? What year was that changed and is it just a matter of changing the wires to the new location or something more involved?

Thanks guys