Then you have been misguided. Although the Macs were originally developed using a combination of 68k assembler and pascal, overtime C and C++ became the languages of choice. Even things like MacTCP and Communications Toolbox adopted many C programming conventions.
You will get better milage from using C eg THINK C5.0, and also have access to a larger store of sample code.
If you want an current example of code written for System 6 then have a look at the http://68kmla.org/forums/viewtopic.php?f=15&t=6767 thread for a download.
The Inside Macintosh series are the place to start and there are consistent rules on converting a Pascal definition to a C defintion.