hotrail, I didn't do the Glock trigger spring so I can't speak for that. However, I would just try changing the sear first and it's not too expensive that way. I'm not a big do it yourself person, but I did change mine and it isn't something that is too difficult plus Apex has a Youtube instructional video available. I didn't put the Ultimate Striker Block in because it does require removing the rear sight but I had ordered Tru Glo TFX Pro sights which I was planning on having a gunsmith install anyway so I just had him put in the striker block too. BTW, this model of Tru Glo's are great, they have Tritium on them for night sights and they also use fiber optic rods for increased vision in the daylight. So now I feel I have the perfect CCW. Regards, Elliot45