[A/S65]

289 hipo casting #s are
C3OE-B 63 5 bolt bell
C4OE-B 64 5 bolt bell , both of these are also used on the 260
C5AE-E 65-67 6bolt bell

One thing to remember is these casting numbers are shared with their lower performance brethern the differance is in the internals.

The 289 hipo had thicker main caps, the extra front counterweight, and a solid lifter cam.

Heads were also basicly the same with the addition of spring pockets, and screw in studs.