by JerrryR » Sat Jan 27, 2024 1:27 am
Hi All,
Here is what I think I know, not necessarily what is correct. Since the big tanks mounted to bosses on the seat casting and neck casting, all XLCHs would accommodate the big or small tank. For the XLCH frame a sleeved hole was installed up front of the seat casting and another hole drilled through the neck casting webbing below the backbone. For an XLH they simply didn't put in the extra holes for the small tank. I contend this was their practice through 66. I believe from 67 on with the new electric start XLH frame holes were factory installed on the XLHs as well to accommodate the small tank. Frames were sold either as an XLCH or XLH frame until 72 when HD went to a common frame with a bolt on upper oil tank bracket for the XLCHs. Doug as far as your 66 XLCH frame I believe it started its life as an XLH frame with somebody doing a bad job of drilling a rear hole for the small tank. Most the H and CH frames I run into have multiple extra holes drilled in the backbone and neck casting to accommodate different tanks over the years. Again, this is what I think, not necessarily what is true. Having said that I do have photos to back up my assertions.
JerryR