Hi Joe, I think in your application this cam would perform similarly to the cam you have (from the factory your engine will have an "A" cam).
My vote for a setup like yours would probably be an aftermarket cam with more duration, like an Enem V15 cam. You could try a Volvo "H" cam also, but I've found the H cam doesn't love the relatively low compression ratio of a B21A and you have to sacrifice your idle and bottom-end performance quite a bit.
If you haven't done it already, a more open exhaust system like 2.25" or 2.5" with a single rear muffler and a mid-mount resonator will make an immediately noticeable difference.
The other thing worth considering is a 123Ignition to replace your stock distributor, as this will allow you to select an ignition advance curve better suited to your setup.
