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Discussion Starter #1
Hey guys, I have a question about heads...specifically '69 RAM AIR III heads. First, are '69 RAM AIR III heads good heads to use? I understand aluminum heads are better, but there is a local guy selling a set for $450. Second, do I necessarily need the full RAM AIR set up in order to benefit from using RAM AIR III heads? Lastly, will after market headers work well with RAM AIR III heads or should I use stock RAM AIR exhaust manifolds?

Any advice would be appreciated. Thanks.
 

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Not an expert. I just like to read a lot. I'm pretty sure the RAIII heads were no different than any of the other D-port, small chambered (72cc), big valve (2.11/1.77) heads from 68-70. They are all desireable, but have the same specs. Maybe there is a difference in flow, but someone with hands on experience could answer that better than me.

I've also read a lot that the RA exhaust manifolds fit and seal better with only a slight loss of power compared to headers.
 

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^^^^^this. Good heads, but you must use dished pistons to use them with today's poor fuel. If you just bolt them on, you will be stuck using race fuel. Too much compression. The RA manifolds are superior to tubing headers for a street/strip car in every way.
 

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OK. Now, I'm more than curious. Would someone please explain the difference between Ram Air III heads and.. say the standard heads you take out of a 400 GTO or Lemans, without Ram Air. I was interested in Ram Air heads when I rebuilt my GTO 400 and a buddy of mine... very knowledgeable about Pontiac engines, I might add sold me a set of nice clean heads for $350, that I rebuilt and used for my project. He said the Ram Air heads weren't worth wasting my time looking for. Besides, he said I'd pay an arm and a leg just to get them and they would not add 13 HP like I had been told in performance when engaging a Ram Air system. He did say something about the fuel of today, vs the fuel of yesterday. Sure it was all about the lead content... back then compared to the crap we're burning now.

So. With that been said should we all be burning Premium (91 or better octane) be a better choice? It would be nice if someone would give us a quick or somewhat detailed education here. My engines not running yet, but soon will.
 

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Discussion Starter #5
Well I was able to pick up the RAM AIR III heads for the low price of $400. They are complete, but could use cleaning and likely a good rebuild (or at least a valve job and new valve guides).

Geeteeohguy, thanks for the heads up on use on the heads. Before I use them, I likely to need to rebuild engine and heads. The heads are #48 heads, whereas my current heads are 7K3 heads.

Besides the pistons and RA manifolds, what else do I need to get the benefit of these heads?
 

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Rvp986, RAIII engines used the same D-port heads as on other engines. The difference was the cam and fresh air intakes. The RAIV, 455HO, 455SD had round port heads which flowed much better and are very rare.
 

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Discussion Starter #7 (Edited)
So in short, if I do not have a Ram Air engine block (meaning the cam and/or pistons), is there any advantage to using RAIII heads (72 cc chambers) over the 7K3 heads (96 cc chambers)? With 91 Octane fuel as being the best here in California, will RAIII heads (with RA exhaust manifolds) perform any better than the 7K3 heads I currently have?

I have also noticed that the casting number "48" is used on both 1969 RAIII heads for the 400 as well as non-RA heads for the 350. How do I verify that these heads are RAIII heads? Also, looking up on a chart of Pontiac heads, I see that the #48 RAIII heads are for a Manual transmission. I am running a TH400 automatic tranny, is this going to be a problem?
 

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Having or not having a Ram Air block has nothing to do with how well the heads work to make power. The crank/pistons/rods make up what is called the "rotating assembly" and are not considered part of the block. The rotating assembly contributes to power output because the combination of bore/stroke defines the swept air volume - cubic inch displacement. The parts are installed into the block. It can be a little confusing because the combination of engine block and rotating assembly is what is referred to as a "short block".

Likewise the cam shaft - not part of the block. The cam, lifters, pushrods, rockers, and valves collectively make up the "valve train". The heads plus valve train make up what is called the "top end" of the engine and is also the second primary determinant of power output because these parts determine peak volumetric efficiency (how much of the swept volume the engine can actually use) and also the rpm where peak VE occurs.


As already noted, RA III's are pretty much the same as any other D-port, large valve head. Do NOT try to run these with flat-top pistons on a factory spec engine even with 93 octane, let alone 91. You might as well take a hammer and knock holes in the tops of all your pistons before you even assemble the engine and save it the trouble of doing it for you. :D

To use them with 91 octane, you'll need pistons with at least 15 cc's of dish volume in the tops, assuming everything else is nominal.

With the 7K3's, you have the opposite problem. ASSUMING that they are actually 96 cc's (they may have been milled, and also untouched heads can vary quite a bit from the published specs), you'll be at 8.144:1 on a factory nominal 400 bored +0.030, lower if it hasn't been bored. IF the heads are 96 cc's and IF they've never been milled, you could mill about .045 off them and get close to 86 cc's, which - along with zero-decking the block - would put you at 9.150:1. But before you start cutting on anything, make sure you measure everything, all the chamber volumes, piston deck clearance, head gasket compressed thickness and gasket bore size - first. Also, milling the heads that much is a one-way street. If you ever need to rebuild the engine in the future and have the heads "decked" to make sure they're flat, there won't be able to without leaving that surface too thin to use.

As far as ID'ing the heads. On any piece of Pontiac cast iron, always start with the 4 character date code FIRST - to determine the model year of the part. Then you can use the casting code to ID it correctly. (If they're model year 1969 with casting code 48, then they're both 350 heads AND RA III heads - it was the same head.)

Bear
 

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What Bear said, in spades. Me, I'd be measuring those 96cc heads and plan on milling them (and possibly the intake) to work on your block for about a 9-ish CR. I have a nice set of Ram Air heads, #12, sitting on the shelf because they are ping monsters on my '67, and that was with 94 octane fuel at the time. Running 87cc #15 heads now, and it's still marginal on a 100 degree day with 91 octane. Rule of thumb, to figure out what octane is needed with compression ratio: 8.7:1 needs 87 octane, 9.0:1 needs 90-91 octane, 10:1 needs 100 octane, etc. With today's pump gas , you are limited to a bit over 9:1 CR with iron heads.
 

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Discussion Starter #10
I am so glad I am not deep into these heads. I am about $400 into them (a trade for a endura bumper). Well, I may just flip them to some one else. I truly wish I could afford a proper engine build and just go out and buy a set of new aluminum heads. But that simply is not in my budget right now.

Now I see why folks just opt to drop in a LS1/2/6.....seems like it might be easier. This is one of those times I am having information overload. All roads seem to be coming back to an expensive rebuild, or just buying a turn key car. The good news is I can easily sell these RAIII heads. From what I am understanding, RAIII heads are the worst of the RA heads, do not make much difference, and these particular ones, are the least desirable of them all. I guess it is time to dump them.
 

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Woah, there, cowboy. Please tell us what you have and what you want to do with it. If you have a stock GTO and want to drive it on pump gas, a cheap-ish set of 87-97cc heads will do the trick. Installing an LS motor is a monumental project, and will net you an engine that has about the same HP but LESS torque than a standard GTO engine. These are simple cars with simple drivetrains. What engine/car/trans/rear gear do you have, and what are your plans? Cruiser, drag racer, etc.
 

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Not trying to hijack this thread but I have kinda the same question as Mr.V
Been trying to help Brent sell a bunch of parts off his 400. Been looking for the going price on a set of date code 69 casting code 62 heads.
Only set I can find anywhere is for sale on ebay.
Guy says they are ram air heads code 62 and is asking $1600 for them. :eek:

If I am getting this right, if there is no code on the heads stating that they where actually off a ram air engine what makes them worth so much more than a set of regular 62 heads. :confused

Bill
 

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A 1969 #62 head is a 1969 #62 head is a 1969 #62 head regardless of whether it was installed on a RA III block or on a "garden variety" YS 400 (like mine were). They were about as good as it got, perofrmance-wise, for Pontiac D-port heads. There's no way to prove whether any given example might have been originally sitting on a RA III engine or not.

... and ... asking $1600 is a good distance away from getting $1600.

Bear
 

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Discussion Starter #14
Woah, there, cowboy. Please tell us what you have and what you want to do with it. If you have a stock GTO and want to drive it on pump gas, a cheap-ish set of 87-97cc heads will do the trick. Installing an LS motor is a monumental project, and will net you an engine that has about the same HP but LESS torque than a standard GTO engine. These are simple cars with simple drivetrains. What engine/car/trans/rear gear do you have, and what are your plans? Cruiser, drag racer, etc.
There is not a short answer to your question. Realistically, I do not want to go through the motions of putting a LS1/2/6/7 in my car. It kind of defeats the nostalgic feel of a classic muscle car. I am not a strip (or even street) racer, so me looking for over 500 HP is not for me. I am a boulevard cruiser that likes the feel of power and have friend bouts of competition with my fellow hot rodders (Mustangs, Camaros, etc).

Currently my car has no engine in it. However, I do have a 1972 YS code 400 engine with a set of matching 7K3 heads sitting on the floor next to my car. Ideally, I want to have a date correct engine in my car that puts out 430-480 HP on pump gas, preferably a Stroker 461. I have a 12-bolt posi rear end with very low gears (not sure specifically but believed to be in low 3's). Again, ideally I will be running 3.31 or 3.55 gears somewhere down the road.

I just contacted a rebuild shop (Precision Engine Rebuild, out of Texas) to price having a RAM AIR III motor built. In my request for a quote, I needed to give the guy details on my car, current motor and what I am looking for. His short response was: "I think we should reman your block and heads." I am not sure what this statement means, but I am guessing from context that I should not go for a RAM AIR III motor and just use the motor and heads I currently have.

Therefore, this leaves me with either using my current engine ('72 YS 400) or continue my search for a '68 Block, and then having it rebuilt into a Stroker 461, utilizing aluminum heads. Which means it will likely be a few years before my car is cruising down the boulevard.

So I am going to flip my RAIII heads to someone that feels it is important to utilize RAIII heads.
 

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At some point, you've got to make some decisions and stick with them. I'll give you a very quick example:
96 cc 7k3 heads on a zero-decked 400 running flat-top pistions = 8.42:1 compression - too low

96 cc 7k3 heads on a zero-decked 461 stroker w/flat-tops = 9.43:1 - too high for 91 octane

96 cc 7k3 heads on a nominal (not zero-decked) 461 w/flat-tops = 9.11:1 - just about right for 91 octane.

So, your 7k3's are pretty good candidates to use on a stroker build.

Want to use your other heads on a 461? It's possible to do with the right parts. KB-Icon IC-981 pistons have a 30cc dish in them. Put those in the motor, don't zero deck it, run those heads with standard gaskets and you'll be at 9.11:1 compression.

I would recommend having the heads reworked to have hardened exhaust seats installed, though.

What you've got to remember is that everything is related to everything else. If you take a bunch of random parts and build a car, you're going to have a car that runs and drives like it was built from a bunch of random parts. Think about every component from the front pulley on the crank to the rear axle, how they all are going to work together and affect each other. Just knowing that your axle is "somewhere in the low 3's" isn't how you do that. There's a world of difference in how a car with 3.31's behaves vs. how a car with 3.55's behaves.

If you want someone to build your engine for you and do it right, as far as I'm concerned there's none better than Jim Lehart at Central Virginia Machine.


Bear
 

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Discussion Starter #16
At some point, you've got to make some decisions and stick with them. I'll give you a very quick example:
96 cc 7k3 heads on a zero-decked 400 running flat-top pistions = 8.42:1 compression - too low

96 cc 7k3 heads on a zero-decked 461 stroker w/flat-tops = 9.43:1 - too high for 91 octane

96 cc 7k3 heads on a nominal (not zero-decked) 461 w/flat-tops = 9.11:1 - just about right for 91 octane.

So, your 7k3's are pretty good candidates to use on a stroker build.

Want to use your other heads on a 461? It's possible to do with the right parts. KB-Icon IC-981 pistons have a 30cc dish in them. Put those in the motor, don't zero deck it, run those heads with standard gaskets and you'll be at 9.11:1 compression.

I would recommend having the heads reworked to have hardened exhaust seats installed, though.

What you've got to remember is that everything is related to everything else. If you take a bunch of random parts and build a car, you're going to have a car that runs and drives like it was built from a bunch of random parts. Think about every component from the front pulley on the crank to the rear axle, how they all are going to work together and affect each other. Just knowing that your axle is "somewhere in the low 3's" isn't how you do that. There's a world of difference in how a car with 3.31's behaves vs. how a car with 3.55's behaves.

If you want someone to build your engine for you and do it right, as far as I'm concerned there's none better than Jim Lehart at Central Virginia Machine.


Bear
I am so confused on this build. It really sucks not being mechanically inclined. It also sucks that I can not justify just spending the money to buy a turn-key motor or car for that matter.

It appears from the wealth of information here, that buying a turn key motor and a turn key rear end is likely the best way for me to go. However, I do not see that happening anytime soon. For I simply can not justify spending $5,000-$10,000 for a motor and then another $2,500 for a rear end. The whole reason I have a project car is that I can not go out and buy a turn key car.

I guess, this GTO project is going to get shelved for the time being, or at least the motor. I will sell off the parts I know I am not using and shelve the rest. If anything, I will focus on getting the chassis, body and interior right, then worry about the engine, tranny, and rear end some time down the road, assuming I do not loose interest first and sell off the whole project.
 

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Well, you can always GET mechanically inclined. :D
It's like anything else. Acquiring the knowledge and understanding is possible with some effort. I knew ZERO about body and paint work until the sheer shock of being quoted 18-grand for a paint job forced me to learn.

Bear
 

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You might be better off buying a complete, ready to go rebuilt engine for your car. Forget numbers matching.....There's a guy on ebay, I forget his handle but can try to find it (he's in the other forums) who has an excellent rep for selling rebuilt 455 engines, ready to go, for about 4k. His engines are mild, durable 400 HP builds that run great and last forever. Simply bolt in and go. 400 HP on pump gas will wake your GTO right up, and your worries will be over. With a mild gear like a 2.93 or a 3.08 and a TH400, the car will do everything well. If you decide to build your '72 YS 400, be advised that it is an excellent, high-nickel block, and is a perfect base for a nice build. Like Bear said, GET educated. It's fun, very gratifying, and it will save you a ton of money. If I still lived in Oakland, I'd be over at your place helping you out.
 

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Ok...did some digging and located the guy. His name is Bob Bohn, and he runs a shop out of Grand Rapids, Mich. called autobahn engines. He has short blocks on ebay ready to go $3600 and up (400cid) and has correct numbers for GTO's, so you could get a 'correct' block for your car. He has an excellent rep on the Performance Years board, and ships these engines crated. If you feel overwhelmed with assembly, combinations of parts, etc, this would be an easy and proven solution to your problem. Just bolt on your choice of heads and sheet metal, and install and drive.
 

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Discussion Starter #20 (Edited)
Hey guys, I am back again with questions on heads. I know one thing, maybe I should go into business locating parts.....call me crazy, but I think it is a bit addictive locating parts.

Anyways, I now have 2 engine blocks and 3 sets of heads. I have had a '72 400 non-Ram Air block with '72 "7K3" heads on it siting in my garage. I now have a '67 400 Block (last 4 of casting is 6133 with a date code F057) with a set of '67 "670" heads on it (which may be RA heads). Plus I still currently have the '69 "48" heads (Ram Air III). Now here is where I need it explained to me in simple terms. I am not a racer, nor do I wish to be one. I like cruising and want to eventually have a 400-450 HP street cruiser. But right now, I just want a nice running car.

Can some one help me understand what I have and which combination will work best on pump gas (even if I have to change pistons, which is expected, right?).

I have heard that everyone wants RA III heads, but I discovered in this thread that that may not be the best choice. I have also heard many people say ignore the RA and just go for "16" or "670" heads, although, "16" heads could also be RA (confusing). It has been mentioned here that the "7K3" heads would work well for a 455, but I do not have that nor do I want that, so I am thinking the "7K3" heads need to go.

I am liking the '67 block and I am leaning towards the "670" heads, but I obviously do not fully understand the mechanics involved. Oh by the way, there is a set of stripped down "16" heads that may be available to me (as if I really need to throw this in).
 
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