Every Glock I have has the 3.5 connector installed. Be it Ghost, Lone Wolf or Zev. This in itself does not lower the trigger to 3.5lbs of pull but does make a difference you can feel. What did surprise me was it varied from model to model with no real reason I could find.
Perhaps it was the degree of wear that particular gun had on it. Perhaps the machining done to that particular connector. But 2 things did happen, one, the pull was lessened by at least a pound and the start to finish of the pull seemed smoother. Install was very easy and I would recommend this upgrade to all.
The Zev had the best results and the quality of the piece seemed to be above the other 2, followed by the Ghost, then the Lone Wolf. All were an improvement. I did not try every model of Ghost out there; I went for the standard model. In addition, I have not swapped them around in all the guns because of time and the degree of difference would probably be minimal but that is just a guess.
I will say this though, I will only buy the Zev V4 connector at this point given the price is no more than a dollar difference between the 3 if you shop around. That can change of course.
Everyone sells a competition spring kit too; I buy the Zev kit by Glockworz because of price, 9 bucks, plus 1 dollar to ship, quality, and fast cheap shipping. It consists of a firing pin spring/ lower poundage, a safety plunger spring/lower poundage and a trigger reset spring/higher poundage. Now installing any one of these springs lowers the pull on the trigger. Most all my guns have the trigger reset spring and this in itself made my triggers even smoother overall.
Did it lower the pull on the trigger, I cannot say positively but it seems to. Perhaps pound.
(Note time) On one of my G21s the reset trigger spring actually made the trigger slow in returning to firing position, well I could not have that, so I tried another reset spring and it worked great...go figure, nothing visible was any different and install was straight forward so I just cannot say why. I actually installed that return spring that gave trouble on another gun and had no issue.
The safety plunger spring. This makes the plunger easier to push down as the trigger bar moves across it, less pull required. I do take my finger and feel the leading base of the hump on the trigger bar for any rough edges, small divots or machine marks that might interfere with a smooth transition of the plunger being pushed out of the way. I use 800 grit sandpaper and lightly stoke the area until it is free of any burrs. Do not sand the high point of this hump, only the ascending base area hump. This appears to lighten the pull a bit and guessing I would say to 1/3rd a pound. Not much but we are adding up here.
Lastly, we have the firing pin spring. This is the money shot. You want it strong enough to fire the bullet of course and so far, I have not had any issues. Time will tell how many rounds go bang before it may need replacing, I do not have a clue at this point. But man, this is where you go into the 2 to 3 pound pull area if you have installed all the above. I would not have this setup on my carry guns but range time or competition.
Oh wow and oh yeah.
Configuring the right setup for you, well do not ask me, that is your decision. Let us do this, what is the gold rule about firing your weapon? You never put your finger in the trigger housing until you are ready to fire it...right? Right! Never.
(NOTE from son the policeman) He told me that they stress and train officers to never attempt to grab at a gun that is falling, let it hit the ground, floor or concrete. Scuff it, perhaps, so what; an accidental discharge is the absolute last thing you ever want to experience. Let it fall, trigger job or not, Let it fall.
You may be tempted to do all the above but think this through, and experiment, add one spring at a time, change this spring setup for that one, do a plunger only, a firing pin spring only, at this point most of mine have the connector and return spring only.
Find your own comfort zone and be smart about it.
As far as I'm concerned Glocks have better triggers stock than other brand guns anyway. All install videos can be found on youtube, some are better than others with the GLOCKSTORE being one of the best, search bar (glockstore) watch the ones that fit your need and decide and once you do one, it is a piece of cake, be it a delicate cake with small pieces of icing.
Be safe, alert, and best regards,
-Robert G. aka cudaviper