Super Jet 64U top end 61x cases?

[agua]

I was out messing with my SN today that i got about a year ago and i never noticed it but the Head says 64U and the cases say 61x?

Theres also a sticker on the side that says PMC North america. Did this come from SBT? [im local]

 

[agua]

Found the awnser on a post made acouple mins ago, But still wondering what PMC is

 

[WFO Speedracer]

Found the awnser on a post made acouple mins ago, But still wondering what PMC is

here is your answer, article is back in 2006 PMC is no longer in business.

http://www.amsnow.com/en/News/Cool ... Engine Remanufacturer Has New Ownership.aspx