78 125 mx cylinder

[Mike Lenz]

OK I got another head scratcher. Only in the 1978 engine book they list a different 125 cylinder for the MC verses the GS. Liner is also a different number between the two. In the 79 book they list only the number for the GS cylinder from the 78 book. Anyone know the difference between the two?  They dont have part numbers on them so... They list a 34 carb for the GS and a 36 for the 78"s also. Anyone got a cyl/engine they know came from a 78 mc model? I sure would like to know the difference!