Dredging this up from the dark deeps!!!!
After looking at pic in post #23, I only wonder more..........
That pic appears to be a C6FE-xxx-A casting. It also appears to have regular spring mounting areas, ie not HIPO 289 style.
I JUST got a ping from a guy in Europe about his 289 in a mid-prod Mangusta. This is the first 289 that I have heard of....or perhaps "almost seen" in a Goose.
Block is a C5AE-E casting and I have yet to hear if it has monster main caps ala hipo 289.........and I want the date code off the block. (His Goose was produced in mid 69....)
Heads: C6FE-A castings, WITH hipo spring pockets! What gets more interesting is the numbers stamped in the valve cover gasket surface above each port.....3 digit numbers suggesting porting and flowing efforts!!!
There are no pushrod guide plates, slots in heads. Screw in studs. Pretty beefy looking springs with orange paint. There could be an inner damper spring...hard to tell from the pics.
So I guess what I am getting at here, is looking at the pic in #23 and what I am seeing, would suggest that Ford was Ford and made copies of the heads with and without the valve spring pocket provisions......
Your mileage may vary!!!
Steve