master cylinder bore

Well I'm wise enough to know when I might be wrong and this is likely one of those times. So I'm going to switch to a smaller bore master. I'm curious to see if there is an improvement.
I did some searching and I found an aluminum body unit with 15/16" bore.
http://www.summitracing.com/parts/dhb-m39476
That master has 3/8x24 threads so here's the adaptor fittings if you've got the larger fittings on your lines like I do.
http://www.summitracing.com/parts/dhb-m39476

Ted