Hey FH, Yeah I said I tried the clark tank, I read your post just the other day came to the same conclusion, it would have had to be cut and welded to work, to bad too I was really hoping for that extra gallon, I bought a stock one after that fiasco. I had to heat and bend it just a little for the plug, and I'm using the NGK shorty that someone else mentioned on here, sorry don't have the part # in front of me, if you need it I can find it. The service honda pipe was a pretty good fit, mine did say Gnarly on it if it makes a difference to anyone. I had read somewhere else that it needed to be modified but mine fit really well, exept for the water hose on the side of the engine I had to ding it pretty good there and then it lined up perfect in the frame, I was a little bit suprised by that because the relationship from the exhaust port to anywhere on the engine should be the same no matter what frame you put a KX500 in. On the down side the trans fill plug is covered, I trimmed the plug down as well, I am looking at an aluminum hex plug online for it I think I found it at RockymountainATV, you need to unhook the springs and pull it out of the exhaust port to get a funnel in it, and just to make it easier I put the water hose on after I mounted the pipe, havn't needed to take the pipe completely off yet so I can't say how that is going to work yet, but for the price and the look, it was a huge time saver when it comes to fabbing one or sending off the bike to get a custom done. And on another note the nickle flaked off terrible when I clearanced it. Hope it was just a bad prep job by FMF. I saw your rear mount too, I did the same thing at first, put the head in the mill and moved the bolt hole closer in and still had trouble making it look nice, I just whacked it off and built a front head stay like a lot of other guys have done on here, that was a shame too because it was one of the reasons I wanted to use an 03 or up frame. For the silencer I just took a piece of thin walled tubing and turned it down till it fit in the FMF pipe and had to cut about an inch or better off the silencer and tig welded the tubing on the end, I'm working on a different set up now, well when I get back in late august that is. Good luck and anything thing I can help with just ask, would love to give back to this site as much as I can.
Yeah stewart good eyes thats in my dads engine shop in Dakota, its an old one but a good one, right next to the honing tank I built when I was in high school, my dad has since put an air ram on it and an amp gauge to monitor the drag of the hone.
scott