Something like a RV cam which is one or two steps above a stock cam. Enjoy it for what you have now. Save some cash for a later build with a newer roller cam block and a set of Vortec heads. These would be the 880 castings and just barrel hone the cylinders and get a stroker kit off ebay and the correct cam for a high torque motor. Feshen the heads and upgrade the valve springs and you will be very happy.