I have a 1996 Chevy c-1500 with the vortec 5.7. My ses light says it has a misfire on #7. I have replaced plugs,wires,cap and rotor and it has made no difference. I took a compresion test and it has 170-175 in all the cylinders. I am lost on this. I would appericate any help! Thanks

 

I would bet it is a spider injection issue or an intake leak. Both are very common on the Vortec motors.

 

Is the spider injection very hard to replace? I done everything else I thought it could be!

 

It involves pulling the upper intake, but I highly recommend while you are that far in to replace the lower intake gaskets as well. Once you have the intake off the spider injection just snaps in along with the 8 legs. It isn't cheap, but fairly simple to do.