It will fit any small block that doesn't have Vortec heads. You can buy a special manifold base that will make it fit Vortec heads, but the base costs BIG bucks. /forums/images/graemlins/frown.gif You have to do some machine work on the stock intake to make it fit pre-EFI heads. The angle on the 4 inner bolts is different between carb heads (used up until '86) and EFI heads ('87-'94 (or was it '95?), then the Vortec heads came out.
If you want to run it on a 350, be sure to get a TPI from a 350. The 305's have smaller injectors and a new set of injectors can run ya $200-400. /forums/images/graemlins/yikes.gif