We have done quite well at Bonneville with Gary Cope's XXO/VGCC with a Kirby/Sissell lump-ported GMC head. Kay Sissell set many drag records in the '70s when he introduced the lump ports in his roadster with a 7 port Jimmy.
I believe the "lump port" is by far the best mod for the siamese port head that has ever come our way so far! I also have had the priviledge of having much experience with working with and also meeting Kay Sissell personally in the summer of 1984, when he visited our race shop and to see first hand his handy work with the awesome cylinder head on Cotton's world record holding "Pocket Rocket" Chevy II. That has long been my inspiration for applying those "tricks of the trade" to these earlier heads!
