Moto Guzzi V700, V7 Special, Ambassador, 850 GT, 850 GT California, Eldorado, and 850 California Police models
If you are looking to replace the original rear drum brake with a disc brake, here are a couple of ways to mount the master cylinder.
Greg Field's method
Thanks to Greg Field for posting this information on the Wildgoose Chase forum. In Greg's own words:
Drums work OK, but it seems I have to grease everything three time to get through a Seattle winter. I'm tired of that, so I grafted on the disc rear end from a T3 before I left for the National in June (2008). Here's one way to do it, for anybody who's interested. The T3 swing arm, u-joint, rear drive, wheel, axle, caliper hanger, and caliper bolted on directly, so no point in recounting that. The difficulty was in mounting a master cylinder. That's easy if you're willing to weld mounts onto the frame, but I needed to mount the m/c without making any undoable mods to the frame. I decided to try to make a plate that mounted to one of the engine-trans studs at the rear and to a standoff from an existing hole in the footboard mounts at the front.
Please keep in mind - I'll convert to the Guzzi Integral Breaking System, your intentions may differ and possibly will require a MC with smaller diameter. Due to my limited time my long term hobby project is still under construction and not tested on the road.
For the bracket I used two 5 mm flatt iron and rounded edge and seam (behind the visible seam) with a file. If I would make it again I'd cut the bracket as single piece out of a square tube (S235JRG2 DIN 2395) - no welding and rounding required.
The 16 mm Brembo master cylinder is used on several small block and big block Guzzi twins, e.g. as rear master cylinder on the MG Jackal. The brake rod is a shortened Cali-III rod.
Mike Ittner's method
Thanks to Mike Ittner for sending me the photos and description in a private e-mail. Mike used an 11 mm Brembo master cylinder (Brembo part number 10.4776.50) with a rod and clevis (Brembo part number 70.6002) and a remote reservoir (Brembo part number 10.4446.40) that Moto Guzzi fit to many sport motorcycles, including the 1992 - 1995 Daytona, 1997 - 1998 Daytona RS, 1996 Daytona Racing, 1996 - 1999 1100 Sport Injected, 1100 Sport Carb, Centauro, V11 Sport, 2003 - 2005 V11 Cafe-Ballabio, V11 Le Mans, 1100 Sport Corsa (MG# 30666900). In Mike's own words: