I have never seen any factory heads with dual drilled intake bolt holes. I think what you have there are either aftermarket castings or modified factory castings.
I remember way back when a member here made a jig he would loan out to drill the heads intake bolt pattern. Never seen or heard of a dual pattern from the factory.
These came off a van sitting in a junk yard back in early 2000s.
No way my memory gonna recall the specifics. lol
It looked 100% factory.
318 came with roller camshaft about 2 years before 360 started to get em.
Pretty sure I read on here a couple decades ago that during crossover the factory drilled the heads with both patterns.
NO.
the early magnum blocks were drilled for rocker shaft oiling, magnum head/gasket blocked it a deck surface. in 92-93 it was either a magnum or a pre-magnum LA head no duel bolt holes on mag heads. roller lifters were the crossover.
that's why someone made up a jig and started swapping on carb/intakes/t-covers hiding magnum roller cam engines in old mopars in the 90s and head rebuilders like Odessa head company in Odessa fl. started doing it to all magnum heads they rebuild and IIRC they cast the EQ heads new and machine them duel pattern. IIRC they do other head work custom order.
the early 92-93 5.2 blocks are best for LA head hybrid mix as they will oil the shaft rockers..
the early pre-magnum 5.2 roller lifters were not oil through and had a solid PRs, then they got oil through roller lifters with the solid PRs. 91-92 pre-mag LA 318 oil through roller lifters/w hollow PRs & through the shaft rockers. then they all swapped to the magnum head/blocks by 94.
any trucks with the 318TBI or a 360headed 4v 318 all got a roller block with a flat tappet cam/lifters.
correct 318 went roller cam in 85 with 360 in 89 with the #308 head (which are the good ones to find)
I remember the moparts rent a jig. seems it went MIA and never showed up again. late 90s
plenty of EQ heads went and still going out as replacements. JYs are full of them by now.
