I've used timney triggers several times. My guess is that you don't have enough relief on the stock. You have to remove alot of material around the triggers for timney's. But then again its hard to tell without being there to see what's going on.

Timney makes a good trigger but I hate how much trouble they can be to fit. For that reason I try to stay away from them. I use jewells for high end and rifle basix for a cheaper option.