Need advice on a 7/8 M/C

[mnm99]

I'm looking to convert my brake system for various reasons from power to manual. It's a 68 Camaro. Currently I have a 1 1/8" master with a dual diaphram booster. The engine Idles at 12" of vac. I ended up moving the pedal rod to the upper hole on the pedal. The upper ratio is 6-1 and the normal power is 4-1. The brakes work well as of now. I'm wondering how it will be going manual.

I called Wilwood and they said I could use either a 1" bore or the 7/8" bore. With a pedal ratio of 6-1 and front calipers with single piston of 2 15/16" size and drum rear brakes with a 10lb residual valve what master should I use? Wilwood said 7/8 would work. Some others say it wont. Many people say a 1" master would be too hard to stop.

Thanks