For the most part, it's a sore subject for googlers and the like. But then the owner of a well known and well respected BMW dealership that I was working at at the time warned me not to install one in my bike. He said that I had to run steel pushrods and raise my 8.5 compression and even then the bike would have no low rpm power and wouldn't idle below 2000rpm. After all, two of his top mechanics were just working on an airhead that has all those problems with a 336 and they couldn't fix it either. ALL of it was BS!
I installed mine without changing anything else and rushed late to a rally with my girlfriend on the back. We were amazed at all the new power everywhere in the rev range. Loaded for camping two up on the interstate through mountain passes and traffic no longer required raking the gearbox. I just kept it in fifth and motored through! Got to the rally and, of course, my girlfriend and I were very excited about it. Some people wanted to hear it run so I started it up. Guru Duane told everybody there that I had in fact installed a 308 because 336's didn't idle that smoothly.
True story! My girlfriend and I were cracking up! I later got it idling even better than that by changing the needle jets!
Then shortly thereafter I put Dell's on. Now 65,000 miles later, my bike is apart at 101,000 miles for the exhaust guides going to crap. Now I am raising the compression (dual plugging it too!) and putting custom made steel pushrods in it!