gearing

First of all, Do you know who built the bike? Was it a drag strip bike with a slick? Or just a cool hot street bike?
Is this thing a KZ 900-1000? looks so in small picture.
With a 17 countershaft! You have 530 chain size. What is the rear wheel from? Another Jap bike, a Harley rim? 17" or 18" diameter.
Need pictures of the rear rim and the offset sprocket and carrier plate with the bearing. Most drag bikes with the big slick or car tire use a 3" offset.
Don't order anything till you know whats going on. If you can find a smaller rear then thats all you need to do.
Go down about 5 or 6 teeth and cut your chain. As long as there is clearance along the way past the swingarm.
Your small avatar picture does not show much.

first off a 630 means a pitch of 3/4 " a 530 means a pitch of 5/8" .measure your chain than go from there.

As I asked long ago, need pics.
Steve

I use this website calculator for gearing predictions. www.gearingcommander.com/

measure your chain size.....the distance between pins, tire circumference, and just pick your bike from the list, and try different combos.

It will be pricey to buy a new offset front sprocket, if it is not worn just buy a smaller rear to get freeway cruising RPM lower.

your bike in the avatar look like it was a dragbike set up with 1/4 mile gearing and has a small circumference rear tire.....so the RPMs will be high on the freeway.....but fun on the street!