Flywheel Bolt thread size?

I have had to change the crank over in my 77 KZ750 twin and now have discovered that there must be two different size flywheel bolts.
The bolt off my original crank is larger than the hole in my new crank.
Everything else fits so i was wondering what year model came with the smaller diameter (around 10mm) bolt so that i can order one.
Because these bolts are left hand thread they are proving hard to find. Any help would be great and if someone has a spare smaller diameter bolt they could sell me that would be even better.
Thanks
Luke

Kawasaki.com is really confusing on this issue, it says the 10mm bolt was used on all the 750 twins, but it also says the larger bolt was used on all the 750 twins.

The following list of models that supposedly use the 10mm bolt may help.

KAF450-B1 (Mule 1000)
KZ400 (1974)
KZ400-A1 (1977)
KZ400-A2 (1978)
KZ400-B1 (1978)
KZ400-B2 (1979)
KZ400-C1 (1978)
KZ400-D (1975)
KZ400-D3 (1976)
KZ400-D4 (1977)
KZ400-H1 (1979)
KZ400-S (Special) (1975)
KZ400-S2 (Special) (1976)
KZ400-S3 (Special) (1977)
KZ440-A1 (LTD) (1980)
KZ440-A2 (LTD) (1981)
KZ440-A3 (LTD) (1982)
KZ440-A4 (LTD) (1983)
KZ440-B1 (1980)
KZ440-B2 (1981)
KZ440-D1 (LTD Belt) (1980)
KZ440-D2 (LTD Belt) (1981)
KZ440-D3 (LTD Belt) (1981)
KZ440-D4 (LTD Belt) (1982)
KZ440-D5 (LTD Belt) (1983)
KZ440-G1 (1982)


Kawasaki.com also says the 76 and 77 750 twins used the 10mm bolt, while the later 750's used what appears to be a larger one. But I wouldn't bet on that being true.

Thanks thats very helpful now i can try Kawasaki again.

Before i do though is there anyone with one of these bolts sitting around from any bike that i could buy? It would just be easier.

Thanks steell.
Where/how did you find that list? Just so i know for next time.

The kawasaki.com parts diagrams, click on a part number, then click on the question mark that appears next to the part number in the new window that opened.

If you're in no hurry, I'll look in my spare parts collection when I get time (probably the weekend), and assuming I remember

Thanks that would be great.

Any one out there able to help?
Please