16 and 17 inch wheels.

[apolloant]

can i replace the 16" on my '79 special with a 17" off another model?

[bikerphil]

Standard wheel on a Special

Yes you can! You'll need the spacers and the caliper mounting bracket off the Standard though. Years 78-81 Standard wheel should fit no problem. You might have to jack the bike up a little higher to install the wheel because the Special's rear fender doesn't swing up out of the way.