The Rochester BC throttle body should be cast iron. I posted the caviat to prevent some enthusiast from trying this method on other carburetors.
There ARE ways to remove the tubes from aluminum or zinc alloy; but require special tools, lots of practice on junk castings, OR a lot of luck. With no offense meant, rather than get someone in trouble, will not answer this question.
Stromberg, Zenith and Rochester used lead balls of varying sizes. Carter used aluminum and brass tapered plugs.
Jon.
