I'm including all relevant pix in this post so you won't have to go back
and forth.
A number of interesting questions were raised so I took the valves out of the head that was on the car and also discovered a part number on it. The part number
is 461541. I was able to find this part number in the 164 parts microfiches and of 9 different head part numbers (3 each B30A, B30E and B30F) this is the
latest (highest) part number of the 9. I was not able to find a part number on
the other head but am sure that it is a 1973 B30F head from a 498100 model
engine.
The first two pictures show both heads, one from the top and one from the manifold
surface. The one with redder paint, oilier and not as dusty is the later head,
p/n 461541.





The light was pretty bright and you cannot see a whole lot except the difference
in bosses for the injector mounts and other features. The intake ports on the later head are 1/64" larger in diameter than the ones on the earlier one.
The exhaust ports on the later head are 1/64" smaller. All ports are round where
they exit the head. The part number on the later head was under the paint on the boss in the center top of the head. Once the paint was scraped off the number was quite clear. As previously mentioned I was not able to find a number
on the earlier head. I do know for sure that it is from a 1973 engine because it was from the original engine in a 1973 model car. Both heads take the same size valves. The intake valves are 1 3/4" diameter or a bit over 44 mm.

The following pictures show the top and combustion chamber from the 461541 (later)
cylinder head. This head is 3.420" thick and I am sure that it has been milled but
am not sure how much. Standard thickness shown in the 1972 green manual for a B30F head is 3.425"





The folowing pictures here are the top and combustion chamber from the 1973 head. This head is 3.440" thick, which is thicker than any of my books show
(but my latest spec is for 1972).





It is my understanding that the later heads were more desirable because the ports
had thicker walls, not that they were substantially different from the factory.
The later heads could stand more extreme porting though, I understand. From the
pictures the differences in the ports are pretty slight. Both heads have the
exhaust ports choked down just below the valve seat. From a cursory inspection
it is not clear if either head has valve seat inserts.
--
George Downs Bartlesville, Heart of the USA!