Help! with brakes

[Chris Jung <cjung@direct.ca>]

Hello everyone.  I was wondering if anyone had some tips on renewing the
rear wheel cylinders on a B.  Mine leak, so I took the bother to change the
seals.  One of them still leaks.  I suppose it's because my brake hone is
not small enough to fit the B's cylinders.  Does anyone has any advice for
fitting the new rubbers?  Also, does anyone know if unleaded fuel is
particularly harmful for a '72 B head?

                Chris Jung,

                '72 MGB roadster,  '89 Mustang 5.0