front tires sizes

Hey I am wondering what size is a lower profile front tire I have the stock 100 90 19 on it now. And I was wondering what size is not as tall that will still work good. I'm trying to get a little more clearance for my header. It is lowered. Id rather not rake it out and. Still keep it lowered. Looking for a good set of tires that will do good on the street and strip.

Try to find a 100/80-19, I've never looked for that size so I'm not sure how common it is, but it would give you approx 10mm (3/8") additional clearance. A 90/90-19 should be available, it will be a bit narrower and also give you about the same 10mm of additional clearance. Not sure what bike you have, but you may also be able to use an 18" wheel from another Kaw model. A 100/80-18 would give you a good 3/4" more clearance than your 100/90-19.

i wouldnt go any narrower on the front wheel if its a streetbike,you dont want the rear wheel pushing the front through a corner on a 500lb bike.

Its a 1978kz 1000 . It has spoke rims. So I don't know if theirs an 18 in spoke wheel for kz's but if their is I'd probably considered that

A spoked wheel would be the easiest type to swap to an 18". You just have to get a rim and spokes that work with your hub, that eliminates all the other complications associated with wheel swaps (like spacing, axle diam, brake related mayhem etc.). Call Buchanans, they are not cheap, but they will know what you need.

Your speedo will be off.

How mich would it be off? And do you know the number and a ballpark number for how much it would probably be

Nah, sorry.