F1SZ-12B579-A is the only p/n I can find for a cobra MAF. This comes from the official Ford book. M-9000-C52 is the FRPP p/n for the cobra kit so the other p/n isn't that. Have no idea where the other p/n came from.
Thanks for the help. From what I understand, the F1SF part number is from the early 90's S/C Thunderbird. I've been told that they have the same functionality.
Thanks for the help. I get conflicting stories everywhere I go. I wish there was some easy way to find out. The F1SZ part number is very hard to find for a good price.
K, here goes. I've been at the local Ford dealer for 10 1/2 years (parts mgr) and the f1sf and f1sz are indeed one and the same. The f on the end denotes the engineering #, the one that the manufacturer used the designate the part. The z is used by Ford to denote the part #. It will work just fine. -Side note, part # called for by Ford is f1sz, # on old part is f1sf