The reason for the shorter insulator block is because people did not like or want the carb hanging out the bottom of the cowl. Can't say I blame them. The new shorter one makes no change in performance. I presume that was what was meant by "reed cage".

Krayzc,

A reed cage keeps all the reeds from getting out and lost at night. Buggers are the devil to find once they get out. You see all the reeds in the cages are usually adolescent male reeds, and you can imagine how their hormones must be raging to make that 115 run so strong. If you have one female reed in the cage the engine misses a lot because all the males will be fighting over her. They will always go looking for female reeds if given the opportunity.