On the standard Model 1911 R1, the dovetail cut is a proprietary cut at approximately 700.
On the 1911 R1 Enhanced and 1911 R1 Carry, the the dovetail cuts are Novak style.
Novak sights can be installed on the standard Model 1911 R1 but the dovetail cuts will have to be changed. Paducah Shooters Supply and Ahlman's, two of our premier field service centers, can make the needed Novak sight cuts for the R1 for around $100. Going through our premier field service centers will not void your warranty. The contact information for Paducah Shooters Supply and Ahlman's is listed below.
Paducah Shooters Supply