Why Won't It Start?!

I have a 96 cav 2.2L that I put a new head gasket on recently. All the plucs are getting spark, the compression is good, the fule injectors are working and all the valves have been timed.
So why wont it turn over?
Any ideas?
I tried getting the starter tested, came back fine. Tomorrow I will check the voltage getting to the starter.
Other than that, ANY input would be appriciated.

did you check the battery?

Checked the battery, full charge. The funny thing is sometimes the engine won't even crank, like it is seezed up. The starter will keep pulling but the engine will not move.

Sounds like a wiring issue, check for grounds and shorts in the wiring to the starter.