In the two-year switch over from 900 to 1000 cc there are some one-year-only parts (there's a tweener in there). I think that's 72-73. Circa 1975 models have that funky cross over shift linkage that everyone throws away, otherwise you should be OK with any year. Sometimes guys knock 79 models because the brake master cylinder is in a different place (a lot of exhaust pipes won't fit), but it's not really a big deal and parts are easy to find.
Most Vintage guys like to restore 1970 and earlier. The XLCHs are somewhat more sought after than the Hs, but because of the magneto ignition (kick only), they can be a bear to start. 67 and later H models have electric start, so if you want an early Sportster with electric, that's the way to go.
The 57 model is arguably the most sought after Sportster (the 59 CH is also prized), but the parts are commensurately high and rather difficult to obtain. Personally, I like the 59-60 H models because of the locomotive nacelle and beautiful gas tank. I'd also love to restore a 59 CH.
Good luck with your search. Be sure to report back when you find your bike.
Last edited by moonwolf; 07-16-2008 at 02:25 AM.
Possessor of many parts that used to be Harley Davidson Motorcycles and someday soon will be again, including a 1957 XL, 1961 XLH, 1962 XLH, 1965 XLH, 1968 XLH...