It's been many years but I did replace all of the trigger parts including sear and safety parts with a post 66 set and then installed a timney.
The biggest hurdle is making the bolt release lever clearance on the side of the action. Don't try to bend it.....it may break...
It's best to machine it using a post 66 reciever for the dims.
Trouble is finding all the parts you need. I had several actions to scavenge from. But using another action might be easier than what you propose, unless you have all the parts.