Help before I go crazy. 99 suburban 5.7 vortec wont start.

[BarryB]

Alright here my story. Bought this 99 suburban with bad motor. The PO said he was driving it when it quit. He had it checked out his mechanic said it had jumped time. I buy it, because I had a 98 5.7 setting in the garage, that had a bent valve. Fixed the valve put it into the burb. get everything back in hooked up. it won't start. I hit the schrader valve on the fuel line. fuel squirts out, so pump is working plus you can hear hit run. It's getting spark pull coil wire spark, pulled a plug and it's firing also. turns over but won't start. Since I had the battery out this whole time and the motor hasn't ran , there aren't any codes. I double checked the distrub. its appears to be right on. I set it with TDC marks on the balancer and timing tab.
So looking for some advice on what to check for. And since I never heard the old motor run, it's making me think it might be something else wrong. I'm using all the stuff from the 98 motor, which I did hear run before pulled. its only problem was the bent valve which I fixed.
Let me know if you need me to explain some more.