Love the videos. You’re from Washington State?
FYI, the Dakota R/T never got the “R/T” head. Those where Mopar Performance heads only and where never put on a production vehicle. So all the production Magnum heads are pretty much the same.
IMO, the JY heads to look for now are the EQ heads that were used to replace the factory heads when they cracked and then run for several years before the rig was junked. I haven’t spotted any, but seems reasonable that if you keep your eyes open they should show up once in awhile.