Here's the basic info page in the XLFs Sportsterpedia:
http://sportsterpedia.com/doku.php/t...972-early_1976
And here's the identification page:
http://sportsterpedia.com/doku.php/techtalk:ih:carb01k
But I'm unfamiliar with a number on the accel pump fitting or if it's significant.
Pics might help.