help finding proper heads...

If the cc's are the same, I'd guess the heads are milled the same. In my experience "J" heads are pretty good as far as cc'c are concerned. Someone probably milled the other head .040 before you got them. There are reference pads in the chambers you cam measure but I guess it is a little late for that. You should be good to go. I'd pull the spacers and readjust the valves since you have adjustable rockers. You can get an adjustable pushrod, mock it up and check side to side. Could be initial wear in has you ticking. Did you adjust them hot? How much preload did you adjust to?