No listing of it in Corvette by the Numbers. Anyone have the book "Chevrolet by the Numbers", should be in there.
SB Head 3946813
Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 1,089
Likes: 43
From: Native Californian CALIFORNIA
Army
SB Head 3946813
Can anyone verify the specifications of this 1969 head? I have been on mortec,nastyz28, etc and only get it was produced 1969 - 1979 for a 350 truck. Through reading articles I believe it is the following:
Valves 1.72/1.50
76cc combustion chamber
runner capacity unknown
Help
Valves 1.72/1.50
76cc combustion chamber
runner capacity unknown
Help
Le Mans Master
Joined: Mar 2001
Posts: 6,640
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From: Ann Arbor Michigan
Instructor
Joined: Dec 2004
Posts: 236
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From: Clearwater Florida
Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 1,089
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From: Native Californian CALIFORNIA
Army
7th Gear
Joined: Jan 2004
Posts: 7
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From: Olyphant Pa
SB Head 3946813
I have a book here by HP books, on How to rebuild your Small Block Chevy and it has a listing of heads and blocks. It states the head that you mention was on a 1969-1970, 350 and that is it.. It gives listings for heads that were installed on high performance/4 bolt mains/trucks/some low perf cars and trucks. List nothing on the specs of that one, only that it was on a 350 for the years specified.
Hope this helps.
Hope this helps.
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Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 1,089
Likes: 43
From: Native Californian CALIFORNIA
Army
I have a book here by HP books, on How to rebuild your Small Block Chevy and it has a listing of heads and blocks. It states the head that you mention was on a 1969-1970, 350 and that is it.. It gives listings for heads that were installed on high performance/4 bolt mains/trucks/some low perf cars and trucks. List nothing on the specs of that one, only that it was on a 350 for the years specified.
Hope this helps.
Hope this helps.
I am still at ground zero need to substantiate the valve, combustion and runner sizing. Someone out there has a reference that will shed some light on this subject. I believe the members of this forum have a great deal of knowledge.
Abby Normal
Joined: Dec 2001
Posts: 53,456
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From: Press "2" for English
there has to be a local speed shop around chino hills (unless kalifornia has outlawed them) you could take those heads to. a pro head builder would probably be able to give you all the specs, and even better, recommendations and advice about the heads.
it looks like you've tapped out the internet resources for a quick answer.
it looks like you've tapped out the internet resources for a quick answer.
Instructor
Joined: Dec 2004
Posts: 236
Likes: 0
From: Clearwater Florida
Not trying to be a SA here but none of the posts say if the head is on or off the motor. If the head is off the motor you can just measure the valves.
Other clues that may help identify it are:
The data code.
The casting symbol.
Drilled for a temperature sending unit
Pressed or screw in studs.
Drilled for a tapered spark plug or a flat spark plug.
Drilled for alternator mounting brackets.
Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 1,089
Likes: 43
From: Native Californian CALIFORNIA
Army
Erv
Not trying to be a SA here but none of the posts say if the head is on or off the motor. If the head is off the motor you can just measure the valves.
Other clues that may help identify it are:
The data code.
The casting symbol.
Drilled for a temperature sending unit
Pressed or screw in studs.
Drilled for a tapered spark plug or a flat spark plug.
Drilled for alternator mounting brackets.
Not trying to be a SA here but none of the posts say if the head is on or off the motor. If the head is off the motor you can just measure the valves.
Other clues that may help identify it are:
The data code.
The casting symbol.
Drilled for a temperature sending unit
Pressed or screw in studs.
Drilled for a tapered spark plug or a flat spark plug.
Drilled for alternator mounting brackets.
Instructor
Joined: Dec 2004
Posts: 236
Likes: 0
From: Clearwater Florida
Flat spark plugs = 1969 and earlier
Tapered spark plugs = 1970 and later.
No temperature sending unit = 1967 and ealier.
Temperature sending unit = 1968 and later.
No accessory holes = 1968 and earlier
Accessory holes = 1969 and later.
You heads conflict with the accessory holes and sending unit information in the book. It may be that those heads were originally intended for a marine application which did not necessarily follow the car and truck applications.
If the heads were fitted with screw in studs from the factory, the motor probably had a high lift camshaft (mechanical). And high lift camshafts were generally associated with higher compression heads and the larger valves.
You may be pleasantly supprised when you find out how those heads are configured.
Good Luck
Safety Car
Joined: Oct 1999
Posts: 4,101
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From: NorCal
These are garden variety 307-350 heads Chevy used for years on 4 door sedans, wagons, Elcos and even some trucks equipped with 2 bbl Rochester carbs. Screw-in studs were NOT available on these, so someone went to some trouble on these for some reason. I've actually used a lot of these heads on engines I built designed for high fuel mileage numbers. I used to build them with high compression, 1 5/8 long tube headers, Edelbrock 2bbl intakes (based on the SP2P if I remember right) and a bunch of different medium lift/short duration high velocity cams, plus some interesting timing strategies depending on the application. 20+ miles/gal. was no problem.
Hans
Hans
