63 P/B Master cylinder

[Gary P.]

I would like to know the difference ( if any ) between a 63 corvette P/B master cylinder and a ( I think impala ) 63 P/B master cylinder. both cylinders ( that I have) are 7/8 bore. only difference I see is that one mounting flange is bigger than the other, about 1/8 ".

[John D.]

Re: 63 P/B Master cylinder

Gary, One difference is in the size of the bore. The Impala is 1" and the Corvette is 7/8" bore.
JD

[Harry S.]

Re: 63 P/B Master cylinder

What are the numbers on the bottom?

[Gary P.]

Re: 63 P/B Master cylinder

Numbers on the bottom are 5462389 on both units.One unit has R1 under the numbers, the other one doesn't have it. The mounting flange is thicker on one than the other.

[John D.]

Re: 63 P/B Master cylinder

Gary, I found my NOS 63 passenger mastercylinder. Forgot it wasn't a PB one.
Casting number on non PB for 63 pass is 5462225. Has a "1" for bore size on top. I used the master cylinder cap assembly on my 63 since my original was pitted.
Note of interest. The original master cylinder cap that was on my 63 since 1970 had the large font. The NOS 63 pass letters(font) are the smaller ones that nice judges now like. JD