Quick MAF question

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. 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.
 
According to this page: http://www.aloha.net/~djhamma/partnumb.htm

The difference in the part numbers, in this case, the "F" and the "Z", denote the design engineering office.

That pretty much goes along with what the dealership told me when I asked them about the same part number.

So, according to the part number, also F1SZ is the Cobra MAF, it originally appeared in the 91 Thunderbird.
 
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