brake upgrade question......

[Eagletucky]

Hello all,

I have recently performed the crossmember and rear end swap on my 61 with a 78 Chevy. The only master cylinder I had was from a early 90's s-10 (no booster). Its all finished and brakes properly bled, but I seem to be experiencing a "long" pedal. The truck stops, but not until the pedal is almost to the floor. Is an s-10 master too small of a bore? Btw, I am running the s-10 proportioning valve as well.

Any suggestions would be apprieciated.

Tim