I have six of thel 6260 versions which the book lists as late '70 and '71 models. They have the bowl vent valve and tube like your later carb. $75 for the pair plus the ride. These came off running engines but have been on the shelf for a while. They might bolt on and work the way they are but it's possible they might need a kit too. The throttle shafts are in decent shape.....some tighter than others but all are good enough to use as-is. I'll pick you the tightest two if you want.
Thanks, Mark