OK. I've looked at the different sites for identifying Pontiac blocks and heads and have determined that my '67 Firebird had a '74 350 engine but the head markings are not shown at any of the sites. The have a 62 on the end port of the head not on the center two ports. The have the GM on the other end port of the head. They also do not have the machined land where the code number would be and there is no date code either. Some one has stamped the number 98800 and J&S on the front machined part of the head.
Any ideas?

I was reading your post and got out my high performance Pontiac number crunching guides from the early 1990's. The only heads that they show had any numbers stamped over port number 1 and 8 are the 1969 RA IV #722 and the 1970 RAIV #614. I also looked for the number 98800 and could not find anything. The only 2 years from 1967 to 1981 that High Performance Pontiac had no casting #s for the cylinder heads by themselves are 1980 and 1981. For those two years they list the engine blocks, intakes, carbs, ect. , but no cylinder heads. I am running a set of number 62 heads that are a 68 casting. The numbers are over the center ports like all the other Pontiac heads. I am wondering if your heads came off of something other than an F-body or if Pontiac reintroduced the number in 80 - 81. I know that some of the parts I have seen over the years for GTO's are different than the F-body castings.

they are 1965 326 heads

look under the valve covers for the date code

very early castings of the #16 heads had #216 on the end port not #16 on the center ports