This is a video explain the differences between what is called ACase and BCase GY6 Engines. Some popular model numbers are 152QMI, 157QMJ and 161QMK and of the Taida 232cc (King of them all).....

In addition to explaining the differences of block, I detail how big each case can bored out.... I discuss short and long case ABlocks and show video of the max tolerances and stock size case openings.

This is the perfect video for anyone that is considering a big bore kit but would like to know more about what fits what.