Yes you can. You will only be able to use 8 of the 14 head bolt holes in the heads, will need stage II intake (off center) and exhaust manifolds and a stage II cam. In a Regal you will have clearance issues with the a/c box. Oh, you might also have clearance issues with the valves hitting the edges of the cylinders on a 3.8 bore motor, depending on the valve size, but I've read that this can be dealt with by valve choice and notching the cylinders.
Should you - here's where everyone is going to chime in and say that stock-style aftermarket heads can flow enough to max out the stock block so why bother. Hey, it's your choice, to do for your reasons.