Sissel gave Headrick one of the first ones cast, in the hopes that NHRA would allow aftermarket heads for Cotton's class in Comp Eliminator.....its still floatin' around somewhere around the shop untouched!
I talked w/Mike Kirby about the ealier versions of those cylinder heads,he stated that the exhaust port actually flows less than a stock cast iron head.
The intake flow was Ok.
Also you cannot get any parts for the earlier version heads at all.
The version that Douglas has is the latest cyl head & flows better everywhere than the older Duggan/Sissell ,Sissell versions.
MBHD
