MPP1423: I have an R&D Conversion cylinder for my Cabela's/Pietta 5 1/2" barreled Remington (pictured below). It was a complete drop-in and was timed perfectly. Works flawlessly and I LOVE it! By the way, My shorty Remington was made in 2004.
Now on my older long-barreled Remington (pictured above) was made in 1987; the same conversion cylinder would not fit in it at all. Much fitting would be needed to make it work in the older gun.