On my PK engine the intake,exhaust,clutch actuator, mag cover, clutch cover, motor mount, and I'm pretty sure the sprocket hardware are all the same. M6 x 1.00 thread. The head-jug studs are bigger but I don't know what they are as I have not replaced mine. Yet. I highly recommend using good quality replacement bolts for the intake, exhaust, and motor mounts at least. The kit supplied hardware is a joke. I have lock tited all my studs in and double nutted everything mounted to them with a lock nut on top and I haven't had any thing vibrate loose yet. This is amazing to me because my bike vibrates...alot.
I believe the good folks at sick bike parts are offering a hardware replacement package for these engines at what seemed like a good price. Something like twelve dollars if I remember correctly. They have an excellent rep for customer service and good products from what I've seen on here. Or you can make a big list and go to Lowes and dig through their bolt bins. That's what I did. If I had it to do again ( and probably will ) I'd just get the SBP deal.
I hope this helps a little. Good luck with your project and have fun.