Durso Overflow Question

[intarsiabox]

I got a 52g tank with two 1" bulkheads drilled in the corners for a good price and the dimensions (30x20x20) are exactly what I needed to fit in my dining room. The problem is that the over flow boxes are only 4.25"x4.25" and go the height of the tank. I found that only 1" fittings from bulkhead to J tube would fit in the overflow area. The durso web site says that my piping for a 1" bulkhead should use 1.5" fittings and piping or it won't work properly. Has anyone had any experience using 1" pipe & fittings all the way through? Any problems? Should I just abandon a duso style and go with a straight 1" pipe with a guard on the top? Any help would be appreciated. Thanks!