I am pretty sure Vortecs are standard small block designs (SBC1, SBC II/LT1).

You'll have to find aftermarket Vortec style heads in order to keep your current manifold/fuel injection. Though you could throw any standard head on there with a new induction system, AFR 195s are probably the best best then.

Standard vortec heads max lift is .450, so a bigger cam is out of the question with stock heads. Could do this with reworked heads, I believe that the valve guide seals have to be machined.