My name is Dewey {Dewey's Custom} and I have been riding and wrenching on H-D's since the late 60s. Just bought a NEW S.E. springer {2007} . For those of you that don't know me , I do head porting and down the road ,will be porting mine. I have ported 2 sets of the 110 heads already. NICE heads. I always modify the valves and put ALOT of attention in a 4 angle seat cut. I am not trying to sell anything ! Don't do that many heads anymore , mostly just a hobby ! Too old ! So far I have installed a Zippers air filter ,it stick out 5/8 inch wider ,BUT, the stock filter has a rubber doughtnut on it that is 1/2" thick ,so when you do a Zippers ,the cover is in the same postion. There is a thick washer inside of the air cleaner cover with 3 spot welds and you need to 'grind' the welds and take the washer out. Have removed the screen on the end of my baffle and punched a 1" hole thru it. Good sound ,not loud at low rpm. Starting to run better,but this is the tightest motor I have ever owned !!! Have 900 miles on it and the motor is off before you get the key all the way turned ! WOW. Anyway , hope I can help with some of your questions.