freshly rebuilt 3.2 liter single overhead cam has spark and fuel but will not start and is backfiring through the intake.

[gagiant34]

I just finished a rebuild on a 3.2 single overhead cam for a 93 isuzu trooper. I'm a very well experienced mechanic but have never had any experience with this particular engine I rebuild the engine with a complete shop manual and I had the heads rebuilt at a headshop and am very sure that I set the timing correctly. when I went to start the engine this afternoon I have no fire and I am getting exhaust out of the intake. does anyone out there have any input on this issue?

[Crvett69]

sounds like the chain/timing belt is on wrong