look at middle hold down clearance on this X head....daylight. Could those be B/RB rocker arms? I'm not sure they would even fit but if he has stock LA hold downs and LA rockers, there should be ample clearance. View attachment 1715816381
They are Mopar Performance Heavy Duty Rockers, bought em new when I screwed her together. Shafts were stock replacement from Advance. Thoroughly cleaned of crap... sent one back for burrs in oil holes