I bought my S&S engine case,S&S Sidewinder kit and STD Panheads from Fog Hollow.They carry every engine part you can think of and always have low prices.Since the Euro is stronger than the Dollar in the moment,it really makes sense and fun to order the stuff from the States but I don't have to tell you that.S&S meanwhile sells complete early Shovel style engines.They also are available as short block and of course in parts so you can build whatever you want to.
www.foghollow.com
www.sscycle.com
Also bought some of the smaller stuff like the outside oil line,Jims lifters and pushrods,pinion gear etc. from Accurate Engineering in Dothan,Alabama.
They also build Custom engines and I think their engines are the best ones money can buy.VERY knowledgable guys and always quick to help.I once asked them for recommendations regarding cams.I still had no computer at that time and had to do it by old-fashioned letter.I received a hand written, two page,highly detailed letter.I highly recommend them ! Maybe this helps.
www.accurate-engineering.com