I'm in the process of doing a T56 swap on my Mach and am really on the fence with this one. The guy who sold me the box was aware of this mod but didn't do it because he said it shifted fine and didn't need it.
Anyone on this thread have lots of miles since doing it and what are your thoughts?
Coming with MGW.
The mod doesn't do anything to the internals or syncros etc. It just reduces pressure on the indent spring allowing the shifter to move more freely. Yes I have many thousands of nicer shifting on my tranny with this mod.