Intake manifolds

Roy Ale

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Oct 20, 2020
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Victoria BC
There is good info on sites about Oldsmobile intake manifolds. The A4 the # 16 and the # 17 . I have a 307 with the #17 cast iron intake . My car is not a hot rod and will never need to go fast . Unlikely my manifold would ever need to be removed from my engine, but should i have a different intake on stand by for just in case it does need to come off ? I know of an A4 aluminum intake for sale . Would this be a better intake for my car ? Sounds like the A4 is not better then my #17 just lighter weight . But the A4 could be better with some work . What is an average price for an A 4 ?
 

Olds 307 and 403

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Oct 4, 2018
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Melville, Saskatchewan
The A4 are pretty rare up here. Most of the early 307's, seen quite a few, all had #17 intakes. Well except a 83 Hurst/Olds. I would not pay much more than $100 for one. Lifting the iron intake off by hand sucks. Any of the iron intakes, the A4 and Performer would all provide similar performance, especially with the small stock cam.
 

Roy Ale

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Oct 20, 2020
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Victoria BC
so the A 4 is rare up here ! I may never use the A4 intake , so do not want to pay more for it than what i could some day sell it for. I like my car and would rebuild the engine some day if need be. the A4 is a lighter weight intake and should be a nicer looking intake than the cast iron intake. wonder what the weight difference might be ? would you bother with this or just clean up the #17 intake when that day comes ?
 

Olds 307 and 403

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I believe 40 pounds, a lot lighter. It is a good match for a 307. For the right price, get it. Just make sure it isn't the A5 with tiny ports.
 
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Roy Ale

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Oct 20, 2020
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Victoria BC
thanks for the info on the A5 .
sounds like the A4 is an air flow match for the 307 but not for the 350. The #17 i have now sounds like it has bigger ports than the A4 .
 

Olds 307 and 403

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Melville, Saskatchewan
The difference between the A4 and #17 intake is minimal, at least from the naked eye difference. The A4 has lines on the port floor. The #16 intake on mid 70's 350 and 403 is also similar. I believe there is about 10 to 15cc difference between the early Olds 350 heads and the 5A 307 port size. At the head opening is similar, the inner port is smaller on the 5A heads. Where Olds heads vary a lot is exhaust ports. All the late 70's heads with the big "A" after number have awful, restrictive exhaust ports. Where the #8 heads just need a bowl hog cutter on the exhaust side bowl to remove a lip under the valve to flow as well as early heads.
 

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