[Scufty]

I have a 427 S/O
I took at look at my heads today ..on the outside the casting numbers are C5AE-F and right beside that is another number 5L15
curious as to what the other numbers are for...I have No numbers on the inside of the heads when I took the valve cover off.
From what I understand these are Med Riser heads from a 65?
I also understand that High riser heads are the best ..where do low riser heads come in? ALso I have a performer 390 intake which I think isnt the best? Whats do you guys think? Holley 750 DP
Solid Cam (mild) Solid lifters, Roller rockers.
There has been a little port work done to the heads.
I also have a Holley STreet Dominator intake sitting here on the bench. Is it any good?
Wondering mostly about the heads and the intake combo as well what I have to be concerned about when purchasing a intake? I was told that you need a high riser intake with high riser heads. Do I need a med riser intake? any input would be great thanks guys