I have to say I am astounded, a firing pin direct from Ruger. Good for you....
....I was unable to buy a grip screw for a blackhawk..........
If you remove the little firing pin and look at the extremes, about 205 across its driving band, and overall length about 444. The driving band length is short, about 78. The recess of the firing pin cavity in the block does have a cylinderical portion with a tapered nose section. The firing pin nose sharpest diameter is around 73. Firing pin nose length is around 318, with a 105 diameter section near the driving band, ie the beginning of the firing pin nose taper. Nominal numbers here of course......
Every No.1 firing pin that I have fooled with over the years, the dimensions are about the same, held the numbers pretty closely.
I hope the new firing pin does something for you.
The exit hole and driving band numbers will be in the mix for holding things on the up and up I would think. One would surmise.........even guess.......that the firing pin exist hole in the block could be bushed. I have never done a centerfire bushing, but several rimfire conversions, which of course...........is another ball game due to the difference in pressures.