4.3 won't idle

I replace the head on my 93 4.3 chevy the head seem to be fine but it not running right now
it won't idle, stall out at idle run like it missing, the spark plugs are new I replace the wires,cap & rotor and the tbi had a plug vacuum pcv port so I replace the tbi there are no vacuum leaks that I can find it not backfiring or anything like that the firing order is right
what am I not seeing ?

I had a problem similar to that on my '87 F-150. The mechanics said it was the distributor, but it could be something totally different with you chevy.