Just installing throttle shafts may not be the fix, the base is aluminum, its most likelt worn too, i would just bite the bullet & get a new base, NOW, AED has stock type base for around 100.00 bucks includeing 4 corner idleing, but for the little extra, you can get a billet like the one i showed you, installing bushings is not that bad, but the tool is about the cost of a billet base, Hmmmmm lol.