Intro to a port job

Update.
Tossed the 308 heads, previous valve job was disastrous to the performance potential. Though they flowed decent...way too much work to bring them all there and still be short of what it could have been. To find a new worthy casting...I waited .. and waited....and finally an old dodge b200 found its way to the local yard. I yanked the heads off of it the day after it showed up. Std 360 4 brl ,steel head gaskets... casting on under side of intake runners is 348915 and the foundry mark I've only seen on 308 heads. Will transfer all hardware/valves to these. Now....that's a digit short of 3418915 J . No letter on the plug side... and DO have smog exh port bumps. Strange and impressive for potential. Had flat face exh valves. Under the covers no numbers other than "74" "25 J" and a "..9?15.. Stay tuned .