Chevy silverado v6

Just replaced the intake manifold gaskets. Put everything back together.
Now the truck will not start.
It is sparking.
When i turn the key over and let the gauges settle the check engine light
stays on.
When i turn the key over it does turn over, but it doesn't fully crank.
Have checked all of the wiring everything is hooked up in the right spot.
Have bled the fuel lines, no air pockets.
Have tried to check if the timing was off. am uncertain if the distributor was
put back correctly.
Any input would be appreciated.