The 3671587 heads are OEM castings that came out around 1973-1974 after the 915 J heads. Early LA-X heads had Indy/RHS (Racing Head Service) cast into them. RHS was likely dropped from later castings.
The "New 2.02" LA heads" that Indy advertises are Mopar Performance 4772576 over-the-counter castings that are very similar to OEM 308 castings but don't have the EGR hole just under the exhaust port. They were cast as 1.88" intake heads but over the years Mopar Performance sold a variety of as-cast, ported, unported, 1.88 and 2.02 assemblies as well as an offset intake pushrod T/A replacement. I guess Indy found a stash of 576 heads somewhere, the last cast iron, standard port LA heads Mopar offered.