S10 wheel cylinder observation

[harris48cars]

Been running the s10 cylinders I bought from one of our venders. While changing brake lines I broke one of the bleeder valves. Went to several parts places that had the s10 manual brake cylinders and at each place the cylinders they had were slightly larger (I'm referring to the cylinder body) than the ones I bought from our vendor. My question is, do some on the manual cylinders have smaller body's or have I been had.
Gary

 

[turbo87adam]

Stock wheel cylinder bore is 3/4". S10 manual brake wheel cylinders are 7/8" bore . Are you measuring actual inside bore diameter or going by outside appearance for comparison ??

 

[harris48cars]

Stock wheel cylinder bore is 3/4". S10 manual brake wheel cylinders are 7/8" bore . Are you measuring actual inside bore diameter or going by outside appearance for comparison ??

Outside appearence. Doesn't seem the 7/8 would be noticeably small than the 3/4 on the outside.
Gary

 

[Steve V]

Pop off the rubber boot and measure the inside.

 

[harris48cars]

Pop off the rubber boot and measure the inside.

Thanks I did. Both bodys have the same 7/8" bore. Now if I could find the smaller cylinder.
Gary