help i have a set of 289 heads i believe they are hipo they have screw in studs and the cup where valve spring goes casting # c80e 289a 0ne head has #8 next to spark plug in front the other head has #11 (8d25,8b26 also on heads) can someone identify this for me.
can't tell you about the casting numbers but look at the guides where the pushrod goes through the head. if it is a hipo head it will have cast in guides and would not need guideplates.
Screw in studs and machined spring cups are correct but the casting number C8OE is wrong, that indicates a 1968 part, and the cast guides had stright edges making the "hole" into sort of a "slot".
hey i have the same problem i bought a for block and was told it was a 302 but i ran the cast number c3oe-6015-b and it cume up like a 1963 hipo i check the heads and it has the screw-in studs and no guide plates it has the the cup that holds the valve spring and the only marking i can find on the heads is c4oe
There were no C8OE 289 Hi-po heads. You've got a set of C8OE's that have had the screw in studs and guide plates added. As for the guides cast in the head, all the pre April 66 289 heads had this feature. And they did not have "289HP" cast into the heads