NEED HELP WITH 3.8!

[Ecnes]

Hey im pretty new to the forums around here but i was having trouble with a 3.8 v6 in my cutlass. ive done a 4.1 intake swap and a 390 carb duel exhaust and jus cant get it to run right! the car has just got a head gasket job with all new valves but it keeps backfiring at the car and tail pipes. ive checked timing and compresstion and everything is good. the only thing ive found wrong so far is that i used a intake gasket for a 3.8 and not a 4.1 which have diff part number. do you think this could be whats wrong? any help it would be great! its making me go crazy! and for all thos that are going to say just put a SBC in! i am but im building it on low funds right now lol

 

[bill]

If the gasket holes matched the port holes and the intake is angled the same as the original, then the back fire issues could be a simple problem to fix. Check spark plug gaps and wires...check rotor button and cap...check all vacuum lines. Maybe the carb is bad? Just my 2 cent...

 

[Ecnes]

If the gasket holes matched the port holes and the intake is angled the same as the original, then the back fire issues could be a simple problem to fix. Check spark plug gaps and wires...check rotor button and cap...check all vacuum lines. Maybe the carb is bad? Just my 2 cent...

well all ignition parts are new. new wires, new plugs which could be a lil burnt by now, new cap and a new rotor. and the only lines r the vaccuum advance brake and pcv

 

[RegalBegal]

This may seem a bit obvious, double check the firing order.

 

[Ecnes]

This may seem a bit obvious, double check the firing order.

yaaa thanks but i checked it about ten million times i noe it by heart now idk whats wrong with this thing

 

[81Regal]

What did you set the timing to? Did you check it with the vac advance hooked up or not?

 

[Ecnes]

What did you set the timing to? Did you check it with the vac advance hooked up or not?

well i did what regal begal sed and rechecked the firing order and 4 and 2 where switched!!! lol im an idiot! damn thing started right up with no problems!!! thanks for the advace GBF! 8)