I went to a swap meet this weekend. While there a friend decided to buy a set of unmatched bare heads based on their casting number. The first head was a 993 casting. 993 appeared on both the bottom of the intake / exhaust runner and the rocker valley. The second head however had a 487x on the runner bottom and a number that ended in 993 just like the previous head. Does anyone know what is up with that? I tried the net but everything I found says that both runner and rocker valley numbers should match. Thanks Guys.

 

Sounds like somebody pulled the old "spec" circle-track trick, of taking a better head than the "spec" and grinding off and replacing the number with the one for the inferior head the "spec" calls for.

So, it's one 993 casting, and one mutilated 487X casting. Not a set at all.

 

Both heads are supposed to be 75 cc's though. You could have different size valves though.

 

How do you do that? You got me now, i'm interested in how though! I can see grinding off the numbers, but how do you put new ones one. Casting?

 

epoxy

 

Duh!

 

Amazing what you can do with a little JB weld.

 

Yeah i was like, man these guys want to win, casting new iron numbers. :lala:

 

http://www.castheads.com/