Hi jk99077, hello everyone,
The following link was not easy to find due to the thread hijack, and therefore, it's misleading title.
I suggest you read
this, then take into consideration how useless HP ratings are. If you still want someone to give you some theoretical numbers, you'll need to include a lot more info.
Quote:
........ how much horse power will early style #6 or7 heads have over small port 1986 heads? ........
350/403 heads will not work on a 307, and no one should expect anything but a performance decrease by using 307 heads on a 350. Anyone who tried would not be interested in documentation, so I don't believe you'll find anyone who has any dyno sheets or timeslips to quote from.
There might be some related flow numbers out there, but you won't find them here.
Regards, Norm
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