If ISR would allow you to run any Kawasaki engine that would be great as long as it fits the rules you should be ok. In IFSX class you can run any engine only that class though. I know for a fact these sleds will not fit in a super stock class or a stock class only a mod or ifs, IFSX class

The original sharks were a titanium cleated track with their own slide suspension 103” I believe. ISR will not allow that track you need to use a rubber track. Al Enno’s sharks are damn near perfect clones including his hood give him a call he probably would sell you a complete sled ready to go. Buy his and change a few things and write down on your cad with all the measurements would be a lot easier to do then starting from pics off the internet. Everything thing that the factory race team told us at Waconia Mn show was all the sharks were aluminum chassis’s and no steel components. The radiators they used were from a kx 125 dirt bike very crude compared to what you can buy now. They made 6 total all started out as leaf spring sleds mid season 5 were turned into an ifs trailing arm. You will run into another problem ISR will not let you run aluminum leaf springs on your skis. Some of the sleds had their gas tank up front where mid season were put on the tunnel. The tunnel that they used was a Sno jet Thinderjet the bulk head they custom made it. ISR will not let you run the trailing arms either its not safe. Safety is key the rules also state a battery tail light, closed in back panel all the clutch guards are mandatory to be closed off including belting on it. It’s nice you want to make one and make the prints I’m trying to help you a few of us has been down this road before and I’m here to tell you it’s down right frustrating because you can be a 100% legal to their rules to have them tell you can’t race it here. The guys from Kawasaki that raced and put these together are great people reaching out to them might be tough. Gregg Channel raced them and very knowledgeable about the sleds. The welder is still around not sure if he remembers all of it just like the others including Jacques but again what was isn’t legal to race now and that’s a fact.

I have much to learn about everything involved in this process, I hope I'm not coming across as a snob, as I'm fully aware, my knowledge is slim compared to some. if anyone has any references to original documents, context, design, notes, anything from the source, I would be immensely grateful, and very little will deter me. the worst that comes out of this will be a set of plans for replica sharks that wont be ISR approved. The best would be the contrary, either way, I'm young enough, to be dumb enough, to go for it lol.

Thankyou - Parker

Racing an IFS Kawasaki are you going for more original because you should look up the classes you plan on racing to see what is allowed I know at Eagle River Derby track Wisconsin they eliminated the 440 IFS & the IFSX 440 class due to not enough entries.
I would also contact with someone from ISR to find out if you can even race it. I went more rounds with them then I’d like to take about especially Eagle River and that was with my first build of the Kawasaki sno pro shark leaf spring 440 l/c super mod class I never got the opportunity to race there because they needed measurements from the factory specs which nobody has, even if I presented to them my prints it still did not hold up water. Their super mod rules are up for talk in April 2025 not sure about the IFS classes you’ll have to contact them. Before contacting them I’d read the rules first they are found on the ISR vintage ice oval page then if you have more questions then write them down when you call. I was just told a month ago it’s better to have it in writing than just showing up to race. I know the leaf spring super mod class allows you to go upto 40” c/c with the carbides. On the IFS & IFSX classes 45” c/c on carbide. I was gonna say with the tunnel I would build it 16 1/2 inches wide and 9” deep or measure up what an Intruder tunnel depth is. Having a tapered tunnel is not easy peazy because everything will need to be custom made because the tracks do stretch.

Greg Lahr  aka Sprocket is the guy to ask questions of.