The jd800 and the jdx600 had the tuned pipe i believe. Hard to find those tuned pipes now. The 00 series went till 75' with ccw engines, 76-79 had the Kioritz engines and the spitfire had the kohler free air. 80-84 were the kawi fireburst engines. I had a mint unrestored 80 sportfire and smashed up the fibreglass hood on first ride. 

and no pictures?!?!?

Yes, it was very good 95% of the areas I rode. Some ice chop as you turned the bend to Kempenfelt, the odd small bit along the western shore closer to Kempenfelt and the usual stacks of ice chunks along the shore along Willow beach, but closer to shore and not an issue when you stay out from shore. Hardly any frozen ruts, possibly none that I came across I think. Pools of slush was not too bad either.  

Noticed this while out riding today 

I had a JD800 My dad had a JD800 My uncle had a pair of JD600's   Not sure what the difference between those ever was? They were both 440's, so ???   Never had any "X's" I think the X's had slide rails in the mid 70's? IDK if there was anything else different (color) than that tho?     None of us had any of the newer "Kawi" powered sleds.   One fella I knew bought a Spitfire for his wife, but that's aboot it that I can think of in our circle.   .