I am doing some work to my 445 and saw where the gasket imprint was a little odd on the header gaskets.
When I got to looking close, 89180 Hedmans for 69-76 360/390 F100s (odd range of years) don't really match up perfectly to anything, except maybe an unmolested C6AE-R
The exhaust port floor of my D2TE-AA heads is approx .110 lower than it should be to match the headers, and a CJ/Edelbrock exhaust port is approx .070 too high.
Not that this is an extreme problem LOL but it begs the question, if you have to drop the header by .110 to make a real nice port match for the D2TE-AA heads, OR, you have to raise the header by .070 to make a good match for the early heads, what did they make the headers to fit originally?
If the application was early 352 it would make sense for a C6AE-R, but 69-76 would be C8AE-H or D2TE-AA
Anyway, looks like a decent justification to make some changes
- 70 Fastback Mustang, 489 cid FE, Victor, SEFI, TKO-600 5 speed, 4.11 9 inch.
- 71 F100 shortbed 4x4, 445 cid FE, headers, RPM intake, 1000 HP series Holley, 4 speed