I did the G5X1 CAM & LS6 P&P Heads and all the other goodies motor wise (no T/C or Rearend yet) but got the car back and it feels actually slower then it was and backfires like crazy. Is this common before the tune. I was expecting it to run bad but not butt slow and sound like a machine gun backfiring so much.

 

Yes. You have a ton more air and not enough fuel to even it out. I personally wouldn't be driving it until I got it tuned.

 

yeah I have decided to do that, I just attempted to drive it once today because I will not be able to get it tuned before I leave for Iraq but I do not want to hurt it and she will just have to sit

 

i think you shoudl investigate a vaccume leak, coil packs harness on backward or cracked plug... no reason it should backfire that much.( to sould like a machine gun) ...... but each car is different.

 

mine is doing the same thing. i have the same heads but cam is almost the same. i will be taking it to get tuned tomorrow. cant wait. car did not really feel slower just not as responsive.

 

there actually was an issue with the vaccum hoses connecting to the valve covers but they thought they rigged it up to where it would be a problem, i checked the connections they made and it seemed to be secure....thanks for the help guys