I sent my 4053DZ carb. out to be rebuilt/restored. The guy called back and told me the bores on the baseplate were too small and this was not the correct baseplate. I bought the carb. used so maybe it is true. In either case, what is the correct bore size? Are the bases more or less universal, such that one from a 3310 with the correct bore size is identical to that of the 4053?