ok,
I have a 51 chevy coe. with the original single pot master cylinder and hydrovac. The master cylinder has a 1 1/4 bore. I am going to remove the hydrovac. and install a hydroboost out of a p30 or mid 90s chevy truck. The Hydroboost has a dual bowl master cylinder. You can install the hydroboost anywhere. I am installing a clutch slave cylinder on the hydroboost. The clutch slave cylinder will be connected to the original single bowl master cylinder. here is a link to show you the idea
http://tdsideas.weebly.com/store/p1/Remote_Hydroboost_Mounting_Kit.html
note:
I may have to change the master cylinder to a 1 inch bore as if you have different bore sizes, your pedal will have a different feel. and i cannot find a clutch slave cylinder with a 1.25 inch bore but did find a few with a 1" bore. The point being, keep the same ratio from the pedal to the hydroboost. the dual bowl master cylinder will most likely have a different bore size.
Hope this helps
Chris