How do I install a split master on a 750 Alfa Spider?

[CLCSF@aol.com]

My 56 Alfa spider race car is presently set up with the stock 1" master
cylinder, Guilia front discs and stock rear drums limited by a bias valve. It
is a great setup, except for the lack of a split system for safety purposes. 
I tried the 69 Duetto master, but it is not big enough and gives too much
pedal throw for effective heel toe operation.
Is there any easy solution ?
Don Queen SF