NZR: S-10 Blazer won't start.

[bschiltz]

So my daily driver; 1991 S-10 Tahoe Blazer, 4.3L 4x4; Was chipping teeth on the flexplate. Over Christmas break I went about pulling the motor and replacing the flexplate and starter. I got everything back together and it won't start. Everything powers on when the key is moved to "on" and you can hear the fuel pump prime. It cranks over fine and you can see the injectors firing. I pulled #1 spark plug to check spark and there was a nice bright spark when grounded to the body and engine both. I thought it might be timing but I set the motor to TDC and set the distributor to cyl. #1. I got some stumbles but nothing convincing. Put a timing light on it while cranking and set it to 0deg without the electric timing thing plugged in (followed procedure on a sticker in the engine compartment). Flipped it 180 just in case but got no stumbles, changed it back and set it to 0deg again and still nothing. I'm absolutely stumped Anyone have any ideas?