Honest, even free, those J heads will cost you a ton to have ported and refurbed. I did my own porting and it cost me close to $700 for valve job, surfacing, hardened seats, new valves, springs, etc... A decent port job will run you 600-900 and then you are talking ede head money which are better OOTB than most any ported early factory iron head.
If you don't want to run Aluminum, look into the new heads available, EQ's RHs, etc... You'll be miles ahead with much less invested.