[mockingbird812]

Here is the info I gathered from the heads that I looked at last night:

* Casting # (both): 3994026
* Casting date (both): E 17 71
* "HI PERF" cast on both
* The Pass. side head had a hump cast in the casting flash line. The Drivers side head did not.

Colvin's Chev. by the Numbers reports that the application was for a 1971 Chevelle 454/425HP. Also there is not a note about a characteristic casting flash line feature (i found a hump on the drivers side head). I thot the only application for that cu.in. / HP combo was for the 1971 Corvette LS6?

Sam