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Discussion Starter #1
I have a 1969 GTO that originally came with a ram air iv engine, I don't have the engine, instead i have a 1970 455 HO without the HO heads, it has standard heads. I want to install all of the ram air stuff without changing the heads and exhaust, intake manifolds. Can I use the stock intake manifold with the ram air stuff (heat ducts, air cleaners etc).
 

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I have a 1969 GTO that originally came with a ram air iv engine, I don't have the engine, instead i have a 1970 455 HO without the HO heads, it has standard heads. I want to install all of the ram air stuff without changing the heads and exhaust, intake manifolds. Can I use the stock intake manifold with the ram air stuff (heat ducts, air cleaners etc).
Too bad you didn't get the original Ram Air IV with the car. Those engines are as rare as hound's teeth...Good luck with the work you want to do...
 

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Hounds' teeth are pretty common.....you must mean hen's teeth.
 

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Discussion Starter #7
Sorry to keep bothering you Bear. Can the cross over be installed with a stock intake? From pictures it seems the ram air iv has a gap on each side for the cross over and the stock intake does not.
 

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Sorry to keep bothering you Bear. Can the cross over be installed with a stock intake? From pictures it seems the ram air iv has a gap on each side for the cross over and the stock intake does not.
No. The RA IV is 2 pieces, the intake and the crossover. The cast iron factory manifold is one piece to include the crossover.

I believe you can very carefully cut the exhaust crossover off of the cast manifold and clean it up (which I have read is done to save weight), then you might be able to use the RA IV exhaust crossover. This would make it look like a RA IV intake, but not 100% on being able to use the RA IV exhaust crossover.

It would be a lot of work.
 

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Discussion Starter #9
It sounds like it would be much easier to buy a ram iv intake. I assume that won't be an issue on the 1970 455 stock heads?
 

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It sounds like it would be much easier to buy a ram iv intake. I assume that won't be an issue on the 1970 455 stock heads?
Intake will work, but the RA IV has a taller intake port 2.18" vs 2.05" and is just a hair wider, there will be a mis-match at the top between the intake and head. If rebuilding the engine, you can port match the heads using the RA IV intake gasket. If you did not gasket match the heads, I might build up the intake port on the RA IV with epoxy and shape it to match the gasket used for your stock heads. Moroso A&B Epoxy - Free Shipping on All Orders @ JEGS
 

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Discussion Starter #11
Thank you the great advise, its much appreciated. I'm trying to understand how the increase in height of the ram iv intake is a problem. Is your suggestion to use the epoxy for aesthetic reasons, or is part of the intake opening exposed above the head and needs to be sealed?
 

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Thank you the great advise, its much appreciated. I'm trying to understand how the increase in height of the ram iv intake is a problem. Is your suggestion to use the epoxy for aesthetic reasons, or is part of the intake opening exposed above the head and needs to be sealed?
No, nothing exposed, it will bolt on as is. The difference in intake height at the top is small, but if you wanted to match the intake to head, then the epoxy to build up the intake side (make it thicker) so you can drop the roof of the intake down in order to then match your smaller head port. This is just a suggestion. You don't need to do it. I don't think the mismatch will present much of a problem on a street car -if it were a race engine, you'd want to match it up so the air flowing down the intake manifold is not interrupted by the lip/edge created by the mismatch of the bigger RA IV intake opening hitting the smaller intake opening in the head.
 

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Discussion Starter #13
Now I got it, your referring to the inside of the intake (port). I assume there is no danger of the epoxy coming off and causing engine damage?
 

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Now I got it, your referring to the inside of the intake (port). I assume there is no danger of the epoxy coming off and causing engine damage?
Correct. The epoxy is a 2 part fuel resistant epoxy. Summit & Jegs and other suppliers sell it. I have not personally used it or had any experience with it. I know that engine builders will use this epoxy to modify intakes to get desired shaping -usually in the area just below the carb or even to fill in sections on a head port to get a certain contour.

You might want to do a web search on "fuel resistant epoxies", or "epoxies used for engine intake modifications" and see what turns up to get some ideas.
 
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