Shorter (ZX6) forks on my GPZ750?

I picked up a complete 2006 Ninja 636 front end (with wheel and brakes) this weekend for $160! He even threw in the complete rear wheel with disc and sprockets!

But anyways, measuring from center of axle to top edge of the fork. I found the Ninja fork is 2 inches shorter than the 1985 GPZ750 fork. So, what are my options? Is this doable? How can I use these parts without looking like a low rider Hayabusa and scraping parts in the twisties? I would like to get close to the same ride height as stock.

Not only will you lose two inches from the forks themselves but keep in mind your new wheel is going to be a smaller diameter than your current front wheel. If you really want to keep the same stock height then you're going to need "gullwing" dropped trees or fork extensions of some sort.

On my Gpz750 I chose Zrx1100 forks as the are relatively long compared to most sportbike front ends.

Later, Doug

Bummer, I wanted some USD forks. But I couldn't pass up the deal. Did I mention they came with the front and rear brakes complete with master cylinders and levers? He even gave me the rearsets!
I'll just have to save it for another project.

I use YZF600R cartridge forks on many of my projects. They are 32 1/2 in. long and Race Tech sells all of the parts needed to make them work on most any bike. They also use a 17mm axle, so lots of vintage kz wheels will work.

If the stock GPZ fork length is 31 inches (approx) and most sportbike front ends are 28-28.5 PLUS they run a smaller rim diamater and low profile tire (another 1 inch difference from the GPZ); how are guys getting away with running an updated front end that is essentially 3-4 inches shorter than the stock one without doing a custom drop down triple clamp? And can even a gull wing top triple clamp give you 3-4 extra inches?

taylee wrote: If the stock GPZ fork length is 31 inches (approx) and most sportbike front ends are 28-28.5 PLUS they run a smaller rim diamater and low profile tire (another 1 inch difference from the GPZ); how are guys getting away with running an updated front end that is essentially 3-4 inches shorter than the stock one without doing a custom drop down triple clamp? And can even a gull wing top triple clamp give you 3-4 extra inches?

Most old bikes that have the USD treatment with the stock clamps are owned by people who don't corner hard. Cornering clearance is already limited, and when you loose 3 inches it gets way worse.
I went with ZRX forks like Doug did because they are only 5mm shorter than stock. I am running a KZ wheel, albeit with a 18" rim. I had to jack the rear end up 50mm over stock to get the trail numbers right because the ZRX clamps have a lot less offset than stock. But less offset is good for stability, and a higher ride height gives more cornering clearance.
Not sure on the GPz but the 78 KZ1000 has 58mm of fork offset which is huge compared to most modern. The ZRX forks have 28mm. If you don't go with custom clamps I would look carefully at the fork offset as small changes can have huge effects on the trail value.

Also if you weren't planning on doing it already you will probably want to brace your frame. once you have stiffer forks your frame will flex more.

this trail calculator may be helpful in guiding your decision, it has a field to change fork length

rbracing-rsr.com/advchoppercalc.html