I just bought a RPM airgap intake for my chevy 350. due to fact says its only intake that will work with vortec heads. the rpm intake didnt come with intake gaskets. so my question is which gaskets like from advanced auto parts or Oreilly's will work properly???

Get a set for a 1996 chevy truck with a 350

Robert,
Which RPM Air Gap did you get ? The stock Vortec heads have a different bolt pattern than older engines and the ports are also slightly different. If your manifold is for the Vortec bolt pattern, then I would use the VOrtec intake gasket, but make sure to get the updated Fel Pro set. Part number is MS98000T

If your manifold is for the old bolt pattern, you will have to get the Vortec heads drilled and tapped for the old pattern. Make sure whoever does it has done them before. You have to use a fine thread bolt in order to get enough threads in the thin manifold flange. Then you use the old style intake gaskets.