Alister
.060 Over
I would strongly suggest removing the AI units from the heads. Triumph makes an 'off road only kit' to plug the AI. The AI causes an after burn in the head pipe and turns them brown and blue.....like yours are right now and they will get worse, much worse as the miles progress.
Already did; that was part of the emissions removal I mentioned. You'll notice in that first pic - the absence of that shiny tube that served as the AI port. Sel-Motion tossed the plug kit in for free with my order. I went above and beyond what the directions said to do, though, removing both canisters under the swingarm, the AI manifold and check valve, and every hose that didn't serve as the fuel overflow, carb vents, and crankcase vent. You shoulda seen the pile of excess parts!
Kept it all, of course. Just in case. They're in a box in the loft of my shed, next to the bigger box of stock Rocket parts (mufflers, cat box, seat, rear shocks, intake crap).