Inliners International Forums General Discussion Drive Train What size slave and master cyl.

I would like use a slave cyl. to activate the clutch on my early 50's chevy. It has a diaphram type clutch and I want to use a 3/4 bore slave cyl. that I happen to have. What size master cyl should I use. My limited knowledge says use a 7/8 just to be safe that it will push the slave cyl. far enough. What is the correct way to figure this out? Thanks.