I was in the exact same boat Fotis, my 'Smith installed the same 28 lb kit you have, I also didn't know which firing pin stop he installed in it, I do know my Springfield trophy match in 45 ACP converted to 45 Super would digest my 185 gr Barnes +P carry load for the ACP just fine, it ran both loads perfect.
After a buddy fired a Chip McCormick 10 shot mag of my hand loaded 230 gr fmj-fp bullets at 1100 fps, he left with my Springfield 45 Super, a couple 10 round mags, and all the Super ammo I had loaded, and I had a check in my shirt pocket.
It was a very powerful and reliable pistol that I miss having around sometimes.
