ENGINE PROBS AFTER MODS!! HELP!!!

I changed my heads, intake and headers last week and when I start it i get a backfire and a low idle. I checked and rechecked the plugs and wires and they are in the right order. Timing seems to be right on. I pulled the upper manifold again and saw that #5 is the suspected backfire. Not sure if all my vacuum line are correct though. I tried looking at the diagram on my hood but can't figure it out. The new parts are Trick Flow Track heat Upper and Lower Intake, a Summit 70mm Throttle body, and BBK shortie Headers. ANY suggestions would be a help.
Thanks!!!

figured it out. it was the lack of a spacer between the throttle body adaptor and the upper manifold which was preventing the upper to seal to the lower manifold because of the EGR connection on the throttle body adapter.