I will say for decades the gold standard move- when adjustable rocker arms were needed was the Crane iron adjustables or even better the Iskenderian Iron adjustables. Same for the LA small block but you can add in the OEM 273 Rocker arms and shafts as a high-quality addition. I'm not talking for all out-race spring pressures but rather when the gear head stepped up to a solid cam or valvetrain that required adjustability. Mancini currently sells a reasonably priced set of LA iron adjustable rocker arms. Do new iron adjustable rocker arms exist anymore for the big block mopar? Isky discontinued theirs many years- possibly 2 decades ago.