Chevy Al 1 1/16" bore

[Eman]

https://www.dragstuff.com/techarticl...sterCylPN.html
Here's a list of sizes and part #'s for Mopar style aluminum MC's.
No matter what MC you use be sure you have a way to retain the pushrod so it cannot drop out of the rear of the MC. A good top pedal stop and a guide for the rod is important. Last year a racer at a local track in a car that was bullt and raced for years had an incident. His foot caught under the brake pedal and he pulled up hard enough to get the rod to drop out. He went off roading and was lucky.