Sorry it took so long to reply we went to the chevy dealer and they worked on it for a half hour broken timming chain and the valves hit the pistons.  The tracker has been siting since my first post and I am tiered of it sitting.  I cant sell it because im still paying on it. So what are my opions can it be rebilt? should i start looking in the junk yard?  if i look in the junk yard or rebeild how can i make sure this dosent happen again?  I also have a chevy s10 blazer with a roten fram that runs great how hard would it be to swap in the 4.3?

I'm right in the middle of rebuilding my 2.0 right now (also a broken chain).  I pulled motor (had about 180K on it) and stripped it down.  Took block, crank and head to machine shop.  Rebored block .020 over, decked block, polished crank (std./std.), valve job including 8 new exhaust valves, 8 guides, and 1 intake.  About 800 for all that work, plus another 400 for rebuild kit.  Plus I'll have maybe another 250 for misc stuff (oil, filters, belts, t-stat, etc).  So I'll be into the engine about $1500 total.  But my 4-door (2000) is in really good shape, so truck will be around for another 6 or 7 years with me.  Now I have all the tools and stuff to pull it, and do this.  If you don't, and you can get a shop to do it for $2K, AND you plan on keeping the truck, I say do it.     On the plus side, the shop should at least include a warranty on their work.  2nd option would be to track down used engine and do a swap in.

Good luck!
NV