I think any sohc engine bolts right in, at least a 75 bolted into my 71. Same goes for the rest of the K bike, it remained the same with minor upgrades. There was a link I can't find where it told you what changed through the years referenced by serial number. I'll post it if I find it.
If you mean running the tires tubeless, no. But you can use tubes in tubeless tires.