Master cylinders...?

[MechaT]

I have access to a either a Nova GTE cylinder or a free Cav 1.6 SPI brake master cylinder. Are either of these larger than my girly SR one?
I noticed the Cav cylinder didn't seem to have pressure regulator valves - the brake pipes just screwed straight into it. Would that actually fit my brake system?

[Ben]

I would say to go for the GTE one as there an easy swap.