I have a swingarm for your 79-81 Ironhead Sportster. I originally bought this for my '68 XLCH to convert it from drum to disc. I have 2 of these so I'll sell the chrome one. Great shape. I can provide pictures if you want.

$200

Oh yeah, no axle, no brake, it does have the pivot hardware, but no wheel. So if you are looking to convert from drum to brake, I can help but I don't have those parts for you.