Urgent master cylinder help pls!

[HongKongPhooey]

I've seen on here that some people have fitted a 19x20 brembo master cylinder..... Can anyone tell me if a 19x18 would be ok on a gen 1 and if so, what would the difference be between that and the 19x20 please?

 

[HongKongPhooey]

Ignore my last, was gonna bid on one on eBay but it's ended now. In any case I've bled the brembos up now and they are awesome... Don't think I need to change cylinders.

 

[FanaticalKilla]

19x20 would be perfect on a Busa. 19x18 would be a bit small. The numbers are input vs output if you wondering. 19x20 less input for more output, 19x18 is the other way around.

 

[HongKongPhooey]

Ok thanks