It depends upon what how much the difference in the gauges is. Porter built some of their catalog tank engines with very wide wheels that you could move the the tires up to three inches. That means that you could go possibly go from 30" to 36" or in some instances from 36" to 42". The latter was the set up on the Carbon Limestone locomotives, their operations being built to 38" gauge. The locomotives from their former quarrying operation that were sold for operation all wound up working on 36" gauge lines (Cedar Point & Lake Erie, the LK&P on Maui , the now defunct Petticoat Junction in Florida to name a few).