Master Cylinder Bore

My car is a 51 Cadillac series 62 mordor. It has stock 4 wheel drums with 1 1/8" wheel cylinders. It has been changed to a hanging pedal on the firewall & has an 11" booster for power brakes.
I'll be buying a 2 chamber master cylinder from Jeg's. Which one do I get?
Thanks in advance for the help.
Cadillac Al

 

First choice the same size as the orignal. With that large of booster 1-1/8 would be OK also . Don't go smaller than the orignal or you will have real touchy brakes.

 

Thanks John
Cadillac Al

 

your local auto parts can set you up with what you need.

 

I always try to get something as close to the weight and proportions of the vehicle its going into. I'd be looking at a '67 GM drum-drum master for a Caddy, Buick or Olds. Pick the heaviest car of the line and it'll be close enough.

Bob

 

My Wagner bible shows you have 1 1/8" front and 1" rear WC's. The master is 1". No current part number given.

 

Thanks to all.
Cadillac Al

 

If the pedal ratio is the same try the factory MC bore size that came with the wheel cylinders you have. The booster size affects the pedal feel. You might have to try a few different MC bore sizes to get it where you like it.