a Sheridan that is not already drilled and tapped for one might be a bit of a pain, depending on your skill level and available machines.
First off, the taps required won't be in any readily available sets. You'll probably need two, a plug style to get things started, and a bottoming to finish up with. The size and pitch are #6x48 the drill size is #31.
The holes will have to be absolutely square with the breech, and not break through into the bolt bore. In addition you have to go real easy when tapping so that the tap doesn't put a bulge into the bolt bore.
OK that's the hard part.
What I usually advise folks that don't want to buy the drill, and taps for the job, or are a little fidgety about the whole process is to glue the sight in place. I generally recommend using #380 Black Max, or the professional series rear view mirror adhesive found in most auto parts stores. Then for a pro looking job, just put a black plastic cap in the one screw hole that shows.
And, on a Sheridan you won't need a taller front sight. That problem will only be with most of the Benjamins.
On all the guns made from the transitionasl onward the Breeches are large and taller. The Williams base had to be moved up to mount higher so the base could clear the breech.
Recently at SHOT I got together with the guys at Williams Gun Sight and we adjusted their tooling so that even tho the sights are mounted higher the base has been clearanced so the top goes lower and will now bottom on the breech rather than the base.
Sheridans and Benjamins from 89 onward have all the same height fronts but how low the peep will go is what limits you.
All 5DSH Production from March mid month onward will be 100% fits all guns. What they have now leftover is a few of the fits the old guns good and needs to be clearanced to work on the newer Post '89 guns.
You will never be able to get a lot of Dans or Benjis to print to POA at 10 yards with 10 pumps but four pumps no problem.
The Williams is a great upgrade and I've drilled and tapped thousands of guns for the sight. Drill & Tap Only is $15 if you strip the guns cam group and trigger/hammer off. I can do the work with the Bolt & Lug still installed so you can leave that.
I will be getting the Old style williams this week so I can take care of the Old Steroids done and waiting for sights.
As soon as Williams makes the newer version they will send those to me as well. Earlier sights can be easily modded with a 1/2" end mill so they will fit late Dans and Benjis. That is $10 including return shipping. We lower the shelf that limits the upper sights downward movement by 60-70 thou.
You can modify the upper or base but the base is easier when you have a Bridgeport. The upper is easier to clearance if your using a file and elbow grease.
"NO GUNS WOULD BE A RIOT"
Later
Tim
Mac1 Airgun