I have a 1996 5.7 alpha 2 barrel set up. I want to switch over to the edelbrock performer manifold. They have two styles a pre 96 and 96 Vortex. Now I know the boat is a 96 but that means the motor could have been in the warehouse and be pre 96. How do you know the diffrence in intakes. Did they change a bolt pattern or something I could spot? Thanks for anyone help.

Look at your current manifold, if it has 12 bolts you have the old heads ( pre vortex) . I think they didn't go to vortex style til mpi motors.

If the valve covers have bolts down the center, instead of around the perimeter, it's a Vortec.

Cuda, and others - those valve covers where used on the earlier 86-95 motors too.

Vortec intakes have 4 bolts per side (total of eight) attaching to cylinder head. These are at straight 90 degrees up and down.

86-95 centerbolt heads (named from the newer style of valve covers) have six bolts per side (12 total) attaching intake to cyl head, with center 2 at 72 degree angles. Others are at 45 degrees.

Pre-86 style have perimeter valve covers and also have 6 bolts per side (12 total) attaching intake to cyl heads. But all bolts are at same angle.

It get's confusing but the above is how to differentiate them from each other.

Thanks guys.