Another possibility is that you might need a spacer between the carb and the intake manifold.

Our host sell them. carb spacers

well the shaft itself is not rubbing the metal device the throttle cable bolts to is rubbing on the intake, if a place a small spacer behind it , will clear I could try filing the manifold

It is not clear where it is rubbing but if you think a washer might work, I suspect it is not the "shaft" that is rubbing but the lever that the throttle cable pulls on. I also suspect you have an after-market aluminum alloy intake manifold.

If the lever is rubbing on the flange the carb mounts to, just file the flange to get the clearance you need. If the lever is rubbing on the intake tube of the manifold, again, file manifold to make the clearance you need. The tube wall is thick enough to accept some filing.

If I am way off base, post a picture showing where it is rubbing. Your throttle assembly may not be correctly assembled or there is some other issue.

My throttle shaft of my SU carb in rubbing on manifold, any one have a notched washer to use a spacer?