I have Diamond W-2 heads that have ben made rectangular. Unleaa you have a high stall and low gears they are dogs until 5000 + RPM. I had to put a small rectangular port dual plane to get them to wotk on my street /strip car. I guess this is off topic but Herb McCandlees told me that rectangular port W2's don't work with an automatic. Too much volume/not enough velocity.