campagnolo pista bottom bracket question

[silverlight]

hi all,
I have recently acquired a campagnolo pista bottom bracket, on the axle it has 68-P-120 with the letter z underneath, does anyone know what the z means? I have another of these but it does not have a z, I believe BB's were made in the 70's thats all i know.
any help would be great. thanks

[rustychisel]

pista means track, measurements mean it's for an English bottom bracket (68mm) and with a width of 120mm.

[GaryF]

I have never heard or read anything about the "z" or lack there of. I don't think it means anything.

The other markings tell you all you need to know about the bottom bracket.