Well for another little tid bit of history on these bikes, there is a reason there are not many "race" parts around.
We have all seen that Moriwaki catalog with all the trick bits. What is not commonly know anymore is as an average guy, you couldn't buy most of them.
You could get the stage 1 cams, stage 1 header, carb kit, ECU (which was an HRC unit) and stacks but that was about it. For all the rest of the parts, you needed to submit your racing resume and they would then tell you if they would sell you the parts or not.
So even back in the day, those parts were all but unobtainium.
Loud pipes don't save lives, knowing how to ride your bike will save your life.