[Healeys] Brake Servo

[Fred Wescoe]

I am installing a brake servo on my late 63 BJ7.

The workshop manual makes reference to the BJ8s having a brake servo (it
was standard on BJ8s) and a 7/8" master cylinder.  I don't know what size
master cylinder is on my BJ7.

So, the question is do I really need to change the master cylinder?  What
size is mine now and what are the consequences of not changing the master
cylinder?  How does a different size master (what I have now) effect the
servo?

What say all of the hydraulic engineers?

Fred
BJ7