My attempt to make Vortec heads look 64 correct, drilled the Vortec intake for the oil fill breather tube, also have valve cover adapters under the 327 covers
what is the story on those accy holes. I had never seen early heads with them before. Maybe big truck accy holes for the air pump for air brakes or something??
That's what I've gathered the few times I looked into them. Lots of "speculation" but no photos usually. https://www.jalopyjournal.com/forum/threads/early-sbc-head-id-help-please.618605/
Some of the truck heads didn’t have any of the typical ID marks. Like PP and 2 humps did but different casting numbers than the non PP heads. We had a set with no casting ID built by a local circle track shop. Had screw in studs and guide plates. Was some guys “cheater” engine I’ve got a c60 I haven’t picked up. One head looks to have an accessory hole. I’ll try to get pics
What I remember building small blocks in early 60s was every speed part came from the Chevy garage and as soon as the factory made an improvement; Hot Rodders jumped on it . 57-60 rocker arm studs bot pinned to keep them from pulling and if you drilled through the center of the stud, they broke. people thought the PCV system was an emission system and removed it. In 63 alternators arrived and generators started leaving the next year. Thank goodness. Corvette rams horn 2 1/2 exhaust became highly sought after (some magazine cars had headers) . Some thought 265 exhaust manifolds were the sign of a not serious build. The 301 was the hot rod elite sbc until '62.
I know the ‘58 Impala air ride option was troublesome and GM replaced the air bags with coils. I never saw the compressor but I suspect it was mounted off the cylinder head, and most likely big trucks with air brakes had that too.
I added engine specs to 1960 photo in my previous post #59. Heads are listed as Racer Brown fuel-injection-type heads.
I dont really have any good photos of the engine of Taboo when it was in its show scene in the early 60s, but the one picture in the rod and custom issue showed the small block wearing corvette valve covers, a tri power set up using 59 and later 2GC carbs and some chrome accessory wire tubes that ran the wires to the front of the block and then under to the plugs. Motor as it sits today.
1958 and 1959 first design cylinder heads had an accessory boss on one end of the head; when installed on the engine, only the driver side head had the boss facing forward. This is where the compressor for the optional air suspension mounted. The air ride was discontinued in mid 1959, at which point a new head casting was made with no boss and the first straight across valve cover bolt holes.