The $60 mask was developed by Bruce Plecan (RIP), as a modified version of the 
$58 mask. It is a 32k image, rather than 16k. 

Bruce used to run a turbocharged grand national on a '749 ecm running the $60
code, with CNP (coil near plug). Bruce was a great guy.

Bruce passed away early May, 2007. He will always be remembered by those he
helped learn EFI 'chipping'. 

-- Joe