If your TR3 has Girling disc brakes with individual master cylinders no pedal stop bolts are required. Comm No - TS13046 onwards
If it is a front drum braked Lockheed system with a dual master cylinder the stop bolts are 1/4 unf x 1.125" long. Comm No - Pre TS13045
see link which shews the Lockheed master cylinder bracket.
http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=8655
Cheers
Peter W