Ok this is a 99 chevy blazer that had to have the heads pulled off and put new gaskets in. all put back together and the timming is all messed up. ive followed the book and set the timming the way it says and still nothing.ive did the 180 on the distributer and still nothing. oh by the way it backfires out of the intake both ways, befor the 180 and after. PLEASE HELP. NO DUMB A$$ things to say ive spent a week trying on the timming alone and pretty pissed about this. thanks for the helpfull comments.

to add to this the son of a bitch will not start thats why im so mad and need help.

If the son of a bitch won't start, how do you know the timing is off?

if its a vortec with a distributor , then there is a special procedure to get it to start , the dist houses the cam sensor , so its gotta be spot on

yes its a vortec. the book says nothing about this though. the timming my be right after all. my uncle came by and said the motor is spinning to freely so some of the rocker arms my be holding a fewvalves open to far. i got to eager to put this back together and didnt check the zero lash while putting back together. ill check into this procedure, thank you 97cavie241s.