The only time I had issues with running a bit rough, was when I had the larger S&S air filter on mine. At speed (70 mph) it would feel like it missed, unless I was accelerating. I put the regular size filter back on and it cleared up. To me, that meant it was running too lean. I also had thought of love jugs (fan oriented to push the air rearward) but the urban cooling fan moves a heck of a lot of air and cuts out at 10 mph when ambient air flow is now passing the exhaust ends. I do have a fan assisted cooler under the bonnet, which dropped my oil temps from the 230's to the 2-teens.
On my wife's heritage softail I put on a fan assisted JAGG cooler and the smaller version of the love jugs, and they do a great job.
