I bought a 96 Blazer off of my brother and long story short he put the engine in it but it needed to be finished. I ended up having to rebuild the heads. I replaced everything to do with the head replacement. I have also replaced the distributor cap, spark plugs, wires, ignition coil, ignition control module, and bunch of other parts. So anyway, I have fuel and spark. I set the timing using the information provided by the service manual and other members on other posts. I am still not getting this thing to start. The compression is good. Fuel pressure is good. I've only ever messed with a blazer once before and all that was, was replace the spider injector. I have noticed that this vehicle is EXTREMELY temperamental. So if you could give me some advice on the topic, I would greatly appreciate it. Thank you.

 

Distributor timing, and Mechanical timing, Verify Both
Mechanical timing must be done with the oil pan off so if the truck is 4WD you're going to have tonnes of fun with that, Align all marks pointing at eachother between the crank and cam and if its a Balance Shaft V6 align the dimple on the bull gear and the scribed circle on the pinion.

For the Distributor align the Rotor at the number 6 mark with the #1 Cylinder (Front Drivers side) at TDC on Compression stroke (Both valves closed)

After that, Verify fuses are all in order and no AntiTheft system trip, should fire over. what are your compression numbers btw?
Oh and you did make sure that the intake is sealed up tight so your not trying to run with a massive vacuum leak right?