Originally Posted by Wrenchbender Ret.
The difference is probably in the angle of the hole for the tube.

Or the bleeder. They could have different bores.

Originally Posted by 55 SHAKER
Just guessing, if all the wheel cylinders were the same wouldn't they all have the same casting number on them? And if they were different they would have different casting numbers on them, just a thought.

I imagine the same casting could have different bores, too.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.