Coal Man:
If you don't mind a slight delay, sending the sear block back to Apex will get you the upgraded block (bigger hole for the spring), and a new spring and plunger, for about $30, including shipping, if you have the DCAEK or similar kit in it. (They just raised the price - I may be about $5 high....) A tad more - maybe about $60 with shipping - for non-customers.
Note that the sear block is NOT considered a firearm, and can be shipped any old way.
You may not be able to get the parts yourself - seems like S&W (and Brownells & Midway) want to sell a whole assembly for about $30 + shipping, and you may not get the new one.
And, fwiw, once you've upgraded the sear, spring, and plunger,
don't touch it!....
(I have to admit that I launched an original plunger with an Apex small spring. Randy upgraded me right before they decided to go public. Same price....)
Personally, I wonder how the heck S&W didn't lose their backsides on this one - they have to lose as many springs & plungers as they ship
....
Regards,