1977 KZ1000 front master cylinder

I hit a deer on my 1977 KZ1000 the other night and the front master cylinder is beyond repair. I have looked on line and see plenty of replacement units at reasonable prices but all have stated for dual disc only. I have a single disc and was wondering if there is any "Real" reason that I can't use the dual disc master cylinder. Any one have any luck or issues with some of the aftermarket units? The unit currently on the bike looks like it might be a carry over from the KZ900 as it has the round aluminum screw on cover.

Thanks

I bought 1 from this place about 9 yrs. ago , it was less money than a rebuild kit for my original M/C, & it still works great to this day
www.ebay.com/usr/usa-motorcycles-inc?_tr...p2053788.m1543.l2754
Pete

The dual disk MC bore is 5/8"; the single disk bore is 14mm. I highly recommend you buy the correct MC, otherwise the brake "feel" is not going to be right. Ed

Go for the 5/8 bore! gives you a reason to go double disc! those other parts are all over ebay and cheap. 4 hole disc's and calipers, the opposite brackets are easy to find, caliper bodys inter change.

OK. Thanks for the responses. One more question....I took off the broken MC and I see no connections/ wiring for activating the brake light. How is this done as those that I see for sale all show an external brake light switch mounted at the bottom of the unit. I looked at the junction mounted between the forks and still see nothing that looks like wiring to me. Am I missing something? Is there some sort of pressure switch that I just dont see?
Thanks again for the responses

On my 1977 KZ650 there's a switch for the front brake light on the lower part of the triple tree (see image below). Ed