Experts.....help?

[bswiv]

Will the dovetail on this mount... https://www.rrarms.com/catalog.php?prod=2169B ...... be the same size as the dovetail on a OLD, 40 years or so, Glenfield model?

You remember the Glenfield line from Marlin, less of everything but very servicable. Is the dovetail for the back sight on that model, a 336 clone, from that long ago going to be the same as the dovetail on newer 336s?

[Jim Watson]

Rifle barrel sights have been in 3/8" dovetails for a LONG time.

The only risk is that it might not be quite in the same place as current models the scope mount is made for. In which case you learn about their return policy, eh?

[bswiv]

Or maybe drill a extra hole or two in the rail?