replacement heads for my 318

Will any of you guys give me some help on heads for my '67 318. It has any Edelbrock alum. intake and 500 cfm Eddy. carb. I have 2 650 cfms if one of them would be better. There is a Comp Cam #20-221-3 in it, valve lift .447 .455. The more research I do the more confused I get. Would stock 308 heads be the way to go or W2s, or are they the same. Would magnum heads fit. Can I keep the same springs and valves. The engine shop that installed the cam and bearings also installed CC lifters #822-16 and CC #901-16 valve springs. Thanks for any help. Dave

302/714 casting heads are good on a 318. If you want to go the Magnum route you'll need new lifters and push rods.