I'm not a fan of the trigger they used anyway, so it was an easy swap. It's been a good while now, but I think I had to do a modest amount of filing somewhere to fit the Timney. But it was an easy install.
Edited to add: As I think about it more, I'm pretty sure I had to file a bit in the slot for the trigger in the bottom metal.
Last edited by WoodsyAl; 06/23/13.