15/16" MC with 2.75" calipers any problems with stopping ?

It's simply a pump, with a removable residual pressure valve to maintain slight pressure in rear wheel cylinders with drums .

I run 3/4 inch M/C with my Supercalifragilistic 4 piston calipers on my roundy-round cars .
Pedals at the top, and very solid, - locks up all 4 - 8" in Hoosier slicks, hot or cold ! !