Wire wheel on a '77KZ650C but keeping dual discs??

So i picked up a parts bike 2 weeks ago for my build, a 1977 KZ650B1- the project bike I am building is a 77 KZ650C1. The difference is pretty much the wheels and brakes as far as I can tell. I wanted to swap the spoke wheels from the B cause they look better.

BUT, I got greedy and still wanted the dual disc brakes up front (the wire wheel only had one). The rotors bolted right on and I put it back together, and then I went to put the cast wheel and the single rotor from the wire wheel (i swapped both sets of rotors cause they are different diameters/thicknesses) on the parts bike just for safekeeping or whatever. When I rolled the wheel under and lowered the forks down on, the clamp seats didn't line up. I didn't notice the discrepancy when I was putting the spoke wheel back on my bike- but once i tried to put the cast wheel on the B there was clearly something wrong.

Is the axle wider on the C than the B to accommodate the dual discs? Which would mean that the fork spacing and the triple clamps are wider too...? Is this true, and can the problem be corrected with spacers? Has anyone done this before? Am I flying too close to the sun with my dual disc wire wheel dream??

The first pic attached is the spoke wheel on my bike lookin nice, and the second one is of the fork not matching up to the cast wheel on the parts bike

I have a b1 and thought they were the same forks but could be wrong. Can you spread the legs to get it to seat or is it to far off. I think it should work. How does the other side of the axle look?

I'm not so worried about actually getting the cast wheel on the parts bike as I am about if the two are different, what that would mean for getting it to fit right and work on the "good" bike (using that term loosely cause right now they're both in pieces ) The weird thing is the spoke wheel with the two discs seems to fit my C just fine. You would think if there is a difference that neither one would swap.I did try spreading the forks on the B and they wont give. I'm going to pull the axle apart tomorrow and make sure its put together right- I'm hoping I just messed something up cause I threw it together quick. That would explain why it seems to work fine on the other bike cause I actually took my time haha

HolyKAW, that looks to be about the difference of the speedo drive on the left side not being seated.

Did you use the spacers from the wire wheel bike?
I dont think theres a differance in the axle itself

According to powersportsplus both the B and C model share triples and axle, so they are the same width.

Direct link: www.powersportsplus.com/parts/search/Kaw...-TIRE-HUB/parts.html

Click the part to see what other model interchanges. You can verify spacers, collars and such this way.

I took both assemblies all apart again and checked them over. Every thing was as it should be, and damarble and wireman are right- the axles are identical, as are the collar/spacer pieces and the speedo drives. I think maybe the parts bike has bent forks? I took a picture but its hard to tell.. Also the P/O had the clamps dropped on the forks an inch or so but that shouldnt make a difference. I tried to spread them and checked the speedo seat but nothing worked.. I guess if all is well with the bike i actually want to ride I'm not going to worry too much about it! Thanks for all your input
first one is the fork sitting properly on the good bike, second is the uncooperative forks on the parts bike

I'm pretty certain you can use the wire wheel & bolt the C discs to it then use those C calipers on the dual discs. I know the fork lowers are different between B & C models & i THINK its the caliper mount thats different.