I owned a set of J code heads that had only the vertical 8 bolt pattern. I bought them from a guy in El Paso, TX who had ordered a set of replacement heads for his '64 427 Galaxie from his local Ford dealer in 1968. They were a 7M date code.
Here’s a picture of them after I had them drilled for 16 bolt pattern:
No, they didn’t. But they did run out of 427 J code heads during production and switched to the 6090 - N heads, but with only 14 exhaust bolt holes drilled (ala 390). Slightly later (April 1, 1968 to be exact) when 428 production started they used 428 exhaust manifolds on the 6090 - N heads. Hope this helps.
The heads with just 2 vertical holes per port are service heads. These are considered low riser 427 heads and this later J casting served as a service part for earlier built 63-65 pre medium riser 427 cars. They were never offered on a production car with that exhaust bolt pattern. I believe the very rare late in 67 W code Fairlanes used the J head as well but would have also used the diagonal 390GT exhaust pattern and manifolds.
The basic answer is you have over the counter service heads from a Ford parts department. There will be no partial vin stamped on the end. They can be drilled for 14 390 GT manifolds or even 16 428 CJ as Royce shared in a previous post.
Jim, On the 427 cars built after April 1 68, what heads and manifolds should have been on them, because as stated above they ran out of J heads, does this mean that when they started using N heads, and also used CJ 2 1/4 manifolds and exhaust ?