[Greg Reimer 7376]

Well, according to the NHRA Tech Bulletin pages, 462 heads are only legal on the 67 Z/28. There's several other accepted heads, which carry over into 68 and 69, but the 68 and 69 cars don't show a 462 head as being legal. The 69 cars had the later casting with the bolt holes for accessory mounting brackets, because 69 was the first year for the long water pump and brackets mounted to the heads and block instead of the exhaust manifolds. All Z/28 engines had the 2.02 intake/1.60 exhaust valves, but the OEM 67-68 heads had no boltholes. 67 Z's were so rare anyway, it's very unlikely anybody is going to find a set,originally.
In the summer of 1980, I wrapped up my days of working in dealers and one of the last jobs I did there was to put a rear main seal in a very nice low mileage 67 Camaro SS 350. Camaro was the only Chevy in the lineup that got the 350, and when the pan was off, I noticed it was a 2 bolt main block but it had a steel crank. I've wondered, since it was a one-off combination if that engine that year only was a small journal 350.That would have been before the changeover to the large journal engine division wide the next year.