1993 Silverado dying when put into reverse or drive
 

Ok guys need help just got done rebuilding my 5.7liter vortec runs ok idles fine but dies when thrown into any gear have replaced iac tpi o2 checked for pump working all of which are good any ideas on what to look for or do next? thanks in advance

Couple thoughts:

1) Vacuum - Double-check all your vacuum, put a vac gauge on it. Book also says PCV. I know it sounds simple, but I've had similar with a bad PVC or a cracked tube to the PVC. Generally it'll run rough even at idle though too. Check TBI base gasket too and brake master vac line. If you go around with a propane torch (no lit, of course), and it 'smooths out' then you've found the leak.
2) Does the ECM think the TCC is 'on' (locked)? A good scan tool should be able to read the status, or you could check the pin at the ECM
3) Double-check distributor. I just had a situation where the 'star' at the top of my distributor was cracked. Don't know how it got that way, but it ran but not very well and wouldn't run at all in gear.

Good luck!

ok thanks for the info i've also read where the alternator if bad can cause same thing which i have noticed when running mine isnt quite up to snuff

another possibility is tcc stuck on

Had a friend had the same issue on his suburban it turned out to be the brake booster had a vacuum leak internally and after he replaced it all was good.