Input needed on engine mods

50* today!Just got back from the junkyard with a set of 302's to put on the 273. I got there kind of late, so I didn't get much of a chance to look around, but I did see a couple trucks & vans with 360's- possibly 308 heads? So, now I'm thinking 3-angle valve grind, any port work? I still have some springs W/damper from my 340 heads, plus the heavier rocker assemblies- should I use these? Does anybody know what the cc volume is on the 302's, and how close it is to the stock 273 head? Thanks.