is it SStock legal to upgrade rear shock to penske?

My 1998 zx6r has racetech fork internals and a penske double-adjustable rear shock. Does having this rear shock mean I no longer qualify for the superstock class?

The stock shock to my knowledge is not rebuildable, or not worth the time anyway.

To get more pickey...I've read the rules and it says the shock can be replaced by the same type.. does that mean I can replace my double-adjustable reservoir shock with a double-adjustable reservoir shock (ie penske) or does that mean I can only rebuild or use the stock shock?

 

You'll be 100% legal. You can replace the rear shock with an aftermarket one and replace the front fork internals to whatever degree you wish. On the front, things that will make it illegal are adding any type of coating to the tubes, using aftermarket (Ohlins, etc) forks or doing any modifications to the exterior of the forks.