I just raised the exhaust port on my generic 66 jug 2.5mm and widened it 3.5mm. Kept the stock floor height, and general shape. Finished with 600grit. Not quite like Rich's finish, but smooth. Widened the intake about 3mm, and it is about 1.5mm taller overall, as I had to re-champher (cham-fer?) the whole perimeter of it. But I got to starin' and head-scratchin' and, having read a book or two on the subject, decided to screw with the tranfer ports. Firt order of bidness was to get my dremel all the way in to the port (Pencil-type/ cable attachment). Went ahead and looked at my CR250 jug for ideas. A dimmly lit light bulb went off somewhere above me, and I began cutting 10mm additional material from the bottom of the jug, under the transfers, keeping the same basic shape.