I don't know if this will be of any use, but here is a picture of a Mallory Unilite rotor. It doesn't fit the stock dist. shaft but a modification might make it work. They also have a low-cost kit to retrofit points distributors here: http://www.malloryperformance.com/ProductDetails.aspx?modelNumber=61003M&productID=5927 I don't know if widening the windows will increase the duty cycle.