Vortec 5.7 No Start

[Creative561]

Ok i had a cracked head on my truck removed head and replaced with a new one from my machine shop guy . now i have reinstalled everthing but i can not get it to start. heres what i have tried

 

1) line up the points and the bottom of the dist. also line up the #8 tab on the dist. housing with the rotor set dist. in facing #1 cyld.

 

2) check wires for spark got spark got compression got fuel still no fire

 

I can here light backfiring also if i turn dist. to far it will backfire through the throttle

 

i have been working on cars for hobby for a lot of years but older cars so i am thinking of older car set ups as far as the dist., and timing gos maybe someone here can help me in the right direction because i am doing something wrong i just dont know what if i had to guess i would say it was timing but i could be wrong

[mxxxz]

Diff . timing . go through you set up again . make sure the number one piston is up to TDC an rotor button is set right .also how did you addjust your push rod after instaling your head ?