906 Heads?

[67 Power Wagon]

OK guys,
I have no idea, reason I'm asking. My Step-son has the chance to get a set of 906 heads, (I haven't seen them yet, BUT he says they're in good unmolestered shape) With having said that, my '67 has a 383 in it, would they fit it AND the intake I have on my running truck with no machine work to the intake or to them? -I ask, as I know the 383 is a B motor and the 906's ARE for a 440 being a RB motor. I am not sure if they are a bolt on, with the stock intake I have or not, but thought for what I may have invested in them, to be worth it for on my truck. As my step-son said, you have a 383 aren't they a bolt on, and I'm just not sure if they are or not NEVER had a set to work with, on, or transplant (in this case) so. here is the best place to find out....

Granted if they were to be shaved, I'd have to shave the intake IF they are bolt on parts, if not "bolt on" parts, I don't think I'm gonna bite.

Any help is greatly appreciated!

 

[greazerlou]

youre good to go buddy... all Mopar big blocks (low-deck "B" motors like the 383 and raised deck "RB" motors like the 440) ALL use the same heads and can be interchanged without modification because the difference is in the intake manifolds, not the heads.

So as long as you stick with the correct intake manifold for your block, its easy peasy bud.
here are some pretty cool Big Block Mopar cylinder head articles written by the great Steve Dulcich if you havent already read them... really good stuff and may even change your mind on those long coveted 906s!!!!!

"Mopar Cylinder Heads" Part 1
http://www.hotrod.com/how-to/engine/5115-cylinder-heads/

"Mopar Cylinder Heads" Part 2
http://www.hotrod.com/how-to/engine/5118-cylinder-heads-ii/

 

[RustyRatRod]

If your 383 has the 915 or 516 closed chamber castings, you will be lowering compression significantly.

Remember, the 915 head came in two variations. The one year only 440 HP head and the style with the smaller exhaust valve. Both carried the same casting number.

Also the 383 standard head was the closed chamber 516 for a time.

 

[oldkimmer]

...........yes the heads r a bolt on, but like stated 67 had closed chambers and 906s came out in 68 till 70 with open chambers.........ur 1967 pistons r also further down in the hole ...........kim..........

 

[67 Power Wagon]

Thanks guys, I was wondering as I want to keep the OEM intake, as I know the heads would "bolt on" BUT wanted to know if I went and got the 906's, if I'd have to change the intake as its a B stock intake, (came with the truck, factory from '67) I knew the 906's would up my compression, SO that might make a little more HP what maybe 35 to 45 HP or so? (that might be a bit high) but its something over what I'm now getting now.

Granted, I THINK I have the 516's.... I'll see if I can see which they are, (hard to see in the '67, as they're "deep" in the engine compartment!)

Better flow, and such what you guys think that might produce in extra HP on top of the 335 I'm now got? My estimate of 35-45 HP sound about right? I'm also thinking of adding headers this spring (I know I've mentioned it) just haven't had the $$$$ to see it through....

Not trying to really "build" it for a pulling truck, I just want a little more "power" for pulling a trailer, with stuff in the bed, as well have power to spare when needed, (torque) well, it will YANK anything so. I'm not to worried about the torque, I think its rated at 425 ft.lbs.

I'm just concerned if I get the heads, I'll have to change the intake, which I can get the heads for doing a bit for my step-son as money is tight, BUT the intake just isn't there..... I may get them, just to have them for when the time comes tho, as I have been thinkin of this now for about a week...... I just had to ask to make sure as I was unsure on the whole thing, never had my hands on a set of these heads..... Always been the 915's and 516's rebuilds, and all never got to work on or bolt on the 906's......So was an unfamiliar part to me. Without removing the heads on my engine now, is there a way to tell if they are open or closed chambers? -This might be an issue I don't want to lower the compression I want to raise it!

Let me know for sure on the intake tho, Much appreciated guys, Thanks for the help!

 

[RustyRatRod]

Te 906 heads will not raise your compression from 516 heads. They will lower it. Significantly.

 

[66fs]

Thanks guys, I was wondering as I want to keep the OEM intake, as I know the heads would "bolt on" BUT wanted to know if I went and got the 906's, if I'd have to change the intake as its a B stock intake, (came with the truck, factory from '67) I knew the 906's would up my compression, SO that might make a little more HP what maybe 35 to 45 HP or so? (that might be a bit high) but its something over what I'm now getting now.

Granted, I THINK I have the 516's.... I'll see if I can see which they are, (hard to see in the '67, as they're "deep" in the engine compartment!)

Better flow, and such what you guys think that might produce in extra HP on top of the 335 I'm now got? My estimate of 35-45 HP sound about right? I'm also thinking of adding headers this spring (I know I've mentioned it) just haven't had the $$$$ to see it through....

Not trying to really "build" it for a pulling truck, I just want a little more "power" for pulling a trailer, with stuff in the bed, as well have power to spare when needed, (torque) well, it will YANK anything so. I'm not to worried about the torque, I think its rated at 425 ft.lbs.

I'm just concerned if I get the heads, I'll have to change the intake, which I can get the heads for doing a bit for my step-son as money is tight, BUT the intake just isn't there..... I may get them, just to have them for when the time comes tho, as I have been thinkin of this now for about a week...... I just had to ask to make sure as I was unsure on the whole thing, never had my hands on a set of these heads..... Always been the 915's and 516's rebuilds, and all never got to work on or bolt on the 906's......So was an unfamiliar part to me. Without removing the heads on my engine now, is there a way to tell if they are open or closed chambers? -This might be an issue I don't want to lower the compression I want to raise it!

Let me know for sure on the intake tho, Much appreciated guys, Thanks for the help!

The 906's are open chamber and will lower compression from 516's. 906's also flow better than 516's, about 20cfm unported, and about the same as 915's. The intake will fit but newer, 68 up intake manifolds, work better. 516's and 915's are closed chamber heads.

 

[67 Power Wagon]

Hmmmm So the intake will work, BUT then I'm not looking to lower compression, I'm looking to raise it, so in this case, I'll pass. (I haven't even seen the 906's yet) so.....

I haven't taken my 383 apart so. I was unsure of fit of it with the intake as well as open or closed chamber from one to the other as I said, I never got my hands on a set of 906's so.... and I think the heads on my 383 from factory are 516's, so.....

I was hoping it go the other way to raise compression a bit but, yeah thats not happening with a bit of what you guys pointed out as well as what I know of the 516's they are open chambered heads, smaller then the 906 chamber so the larger chamber of the 906's will lower it even further, not what I'm looking to do! (I was hoping the 906's were closed chambered) as my pistons are down in the hole anyway..... And here I was hoping for a quick bolt on...... ya know?

Anyway, thanks guys! Much appreciated, it looks as tho what I'm trying to achieve is not gonna happen all that easy! As I am not looking to rebuild the whole engine, I was simply looking for some bolt on power, nothing serious, just a little more and I thought I could have had it at my finger tips.....

We'll leave it be for now, maybe in the future but the truck runs and runs GREAT, so..... I'll let it be for now! Plus, winter is coming, (I'll need the truck a lot sooner then later!)

Thanks guys!!!!!

 

[RustyRatRod]

No, you don't know anything about the 516s apparently, because you say they are open chamber. They are not. They are closed chamber.

 

[RustyRatRod]

First the 516 closed chamber head. The 915 heads are very similar. Then the 906 head. See the difference?

 

[66fs]

First the 516 closed chamber head. The 916 heads are very similar. Then the 906 head. See the difference?

I think RRR meant 915 heads instead of 916 heads above.

Even with the loss of compression the 906's will make more power than 516's. Compression is an adder, and flow is a multiplier. "67" 383's had decent compression, unlike the mid to late 70's 400's and 440's.

All that been said the 516's are probably a good fit for your truck.

 

[RustyRatRod]

I think RRR meant 915 heads instead of 916 heads above.

Even with the loss of compression the 906's will make more power than 516's. Compression is an adder, and flow is a multiplier. "67" 383's had decent compression, unlike the mid to late 70's 400's and 440's.

All that been said the 516's are probably a good fit for your truck.

Yes I did. Thanks for catching that. I changed it.


I agree that the 906s are superior in flow. I was merely letting him know he will have a pretty big compression loss........but I am not sure in this case the flow will trump the compression, because it will be a BIG loss.

As previously stated, his engine has pistons with a shorter compression distance. So that means the pistons in that engine sit lower in the bore at TDC than an engine that would have had 906 heads. IMO the compression loss will be at least 1.5 points and possibly more.

 

[66fs]

You are probably right. I'm not sure there would be much gain, if any, for the time and trouble of a head swap. I'm not sure what compression ratio a 4 barrel truck had in 1967. If it was a 4 barrel car engine in 1967 it would have "theoretically" been about 10:1. I know you know what I mean. So, if it ended up around 9:1 no big deal in my mind. Keep up the good work.

 

[67 Power Wagon]

First the 516 closed chamber head. The 915 heads are very similar. Then the 906 head. See the difference?

Rob, YES I "know" the difference from open chambered to closed chambered heads, I did NOT need that, I DIDN'T know that the 906s were open chambered, I DID know the 516s were open chambered. -As I clearly said, I was and still am unfamiliar with 906 heads!

So the clarification was unneeded, it was the difference between the 2 head types!

 

[67 Power Wagon]

I think RRR meant 915 heads instead of 916 heads above.

Even with the loss of compression the 906's will make more power than 516's. Compression is an adder, and flow is a multiplier. "67" 383's had decent compression, unlike the mid to late 70's 400's and 440's.

All that been said the 516's are probably a good fit for your truck.

Sadly, its got 516's on it..... SO, was looking for better options as a bolt on (no machine work, or purchasing extra parts to make it all work)

I'd rather build compression, BUT right now, its in fine running shape, (guess I have some thinkin to do before I indulge...)

 

[RustyRatRod]

Rob, YES I "know" the difference from open chambered to closed chambered heads, I did NOT need that, I DIDN'T know that the 906s were open chambered, I DID know the 516s were open chambered. -As I clearly said, I was and still am unfamiliar with 906 heads!

So the clarification was unneeded, it was the difference between the 2 head types!

No, you still don't "know". Clarification is clearly needed. The 516 is a CLOSED CHAMBER head. Not open chamber.

 

[mguner]

516s are also CLOSED chamber heads with 1.64 exhaust valves. Just have them massaged a little and get 1.74 exhaust put in them. They will be fine for a mild 383.... You will also notice the 516 head has no 1" freeze plug on the ends like the other castings mentioned.

A 67 383 in my 68 Coronet 500

 

[67 Power Wagon]

First the 516 closed chamber head. The 915 heads are very similar. Then the 906 head. See the difference?

Now for me to clarify, these 2 seen pictures, show the BOTTOM of the heads, on my 383, I have NEVER had the heads off the block, so this I have never seen, I looked at my heads yesterday, they seem to be the 516's. NOW, my question is, if I look at them, still bolted on the block, is there a way to tell the difference what head type they are, without removing one of them?

I had confused the 915's, and 516's. SO, if I were to find a bolt on head, to multiply the HP, what head be a better choice, without a total "rebuild"? As I'm not wanting to sink that kinda cash into the engine when really, theres nothing wrong with it factory. SO if I can change the heads to get a little gain, I'd be happy. I just don't want to replace the rotating assembly as I'm not looking to go "that far", for now, as I want to keep it a daily driver.

Sadly tho, I do not trust my local machine shops for any type machine work as the couple thats local, don't have the best of reputation so.... Bolt on's as I can get them, it is.... That is, if I can get bolt on parts.....

 

[67 Power Wagon]

516s are also CLOSED chamber heads with 1.64 exhaust valves. Just have them massaged a little and get 1.74 exhaust put in them. They will be fine for a mild 383.... You will also notice the 516 head has no 1" freeze plug on the ends like the other castings mentioned.

A 67 383 in my 68 Coronet 500

I'm at the garage again, I'll look and see if the heads on my 383 have the the freeze plug, or not, I didn't notice when I was there yesterday (I just now seen this post) so, next time I'm over at the garage, I'll look!

HMMMM

 

[RustyRatRod]

If they are 516s, then you have closed chamber heads. If you're not looking to get the pocketbook out, leave them alone.

The only other factory head that would be a bolt on upgrade would be the 67 only HP 440 casting, the 915. They also have closed chambers, but have the larger exhaust valve and much better ports than the 516.......however, people think they are worth stupid money......so you may as well go with some Edelbrocks or Trick Flows. ....so if you're not lookin to drop a lot of coin, leave it buttoned up.

 

[67 Power Wagon]

If they are 516s, then you have closed chamber heads. If you're not looking to get the pocketbook out, leave them alone.

The only other factory head that would be a bolt on upgrade would be the 67 only HP 440 casting, the 915. They also have closed chambers, but have the larger exhaust valve and much better ports than the 516.......however, people think they are worth stupid money......so you may as well go with some Edelbrocks or Trick Flows. ....so if you're not lookin to drop a lot of coin, leave it buttoned up.

I have to look Rob, As I'm unsure, as I haven't needed to remove the heads. BUT thats not to say if something comes along like the 906's my Step-Son has now, I can get the set for stupid cheap money really, as he got them in a trade, and has nothing to put them on or need them on. He's got no Mopar stuff right now. So..... I was "hoping" as it be nice to do something, like I mentioned a little more to spice up my '67.

NOW having said that, there are a few guys that come around the garage, that gets crazy **** for what seems really good prices, and the Step-Son passes that onto me, as I help him in the garage when I'm able. Let me ask ya, what ya think of the wheels and tires on my truck? (Got the wheels, and tires for $175.00 5 tires, 5 rims.) NOT each, for the "lot"..... Those 906 heads hes now got? He paid $200 for the set! This is what I mean by stupid cheap, the tires and rims have been on my truck since August of 2013! The 906 heads, I have yet to see, he got them today, and I haven't been at the garage since yesterday! SO..... I'm sure I'll get to see 'em at some point. I may still take them to see if I can't make a few bucks off them, but thats one thing. $200 for the set, I don't think is to bad. From what I've heard from him, they're stock, as-built from Ma Mopar.

Anyway, we'll see. As I'm not sure, I got a few "eyes" locally to see whats out there, and what they know for Mopar (Alot of Ford guys here, but have a bit of Mopar stuff laying around...... Odds and ends) so..... I'm trolling for what I can find.

Sadly, as far as dropping "coin" IF I had it, I would, I just don't have a lot to spare right now so, I have to be careful how much I get into.

 

[forphorty]

I have to look Rob, As I'm unsure, as I haven't needed to remove the heads. BUT thats not to say if something comes along like the 906's my Step-Son has now, I can get the set for stupid cheap money really, as he got them in a trade, and has nothing to put them on or need them on. He's got no Mopar stuff right now. So..... I was "hoping" as it be nice to do something, like I mentioned a little more to spice up my '67.

NOW having said that, there are a few guys that come around the garage, that gets crazy **** for what seems really good prices, and the Step-Son passes that onto me, as I help him in the garage when I'm able. Let me ask ya, what ya think of the wheels and tires on my truck? (Got the wheels, and tires for $175.00 5 tires, 5 rims.) NOT each, for the "lot"..... Those 906 heads hes now got? He paid $200 for the set! This is what I mean by stupid cheap, the tires and rims have been on my truck since August of 2013! The 906 heads, I have yet to see, he got them today, and I haven't been at the garage since yesterday! SO..... I'm sure I'll get to see 'em at some point. I may still take them to see if I can't make a few bucks off them, but thats one thing. $200 for the set, I don't think is to bad. From what I've heard from him, they're stock, as-built from Ma Mopar.

Anyway, we'll see. As I'm not sure, I got a few "eyes" locally to see whats out there, and what they know for Mopar (Alot of Ford guys here, but have a bit of Mopar stuff laying around...... Odds and ends) so..... I'm trolling for what I can find.

Sadly, as far as dropping "coin" IF I had it, I would, I just don't have a lot to spare right now so, I have to be careful how much I get into.

Sorry, but $200 is not stupid cheap for stock 906s. In fact, he spent way too much for them, IMO. If they were recently completely rebuilt, then maybe.

 

[67 Power Wagon]

Sorry, but $200 is not stupid cheap for stock 906s. In fact, he spent way too much for them, IMO. If they were recently completely rebuilt, then maybe.

I'm not sure I still have yet to see these, but he got them for $100 a head $200 for the set..... Cleaned up (he said) and had the valves replaced, and he thinks the springs replaced. NOT sure if any machine work was done, (I haven't looked at them myself yet)

When I get to see them, I'll post what they are/have done/ and condition.

 

[67 Power Wagon]

Talked with the Step-Son while he was at the garage on the phone had him pop the hood and look at the ends of the heads for freeze plugs, turns out I do have 516 on it...... Neither one of the heads have freeze plugs in them, so Rob, you'd be right, I'd have to find the '67 HP 440 "915" heads to go where I was hoping the 906's would. I wanted to build a little compression as I know my pistons are down the hole a bit, and closed chamber head with bigger valves could only add some power. as well as have a bit of compression added into it all.

SO, for another day, I'll leave it alone! Or at least till I'm able to come up with some more parts, like a rotating kit to raise compression for the 906's if he still has them at that time as he says I'm the only person that had interest so..... HOWEVER, I do still want to see the heads he's got to see if they 1. are 906's as he was told, and 2. to see if they have ANY work done to them including what he was told they got. As I myself really don't know, and he only knows what he was told. personally I think he can't tell as it sounds the heads have sat for a bit and got some rust to cover things up that was done (needing more work to clean 'em up) so. I really want to see for myself.

I asked him on them tho, he got the heads, and a Mopar 318 or 360, almost complete, as well as an 833 tranny, and some other stuff for $200. Granted, I haven't seen any of it yet, and he doesn't know when any of it was "working/ran" last, or if it was just left-overs..... The LA he says isn't complete! Missing all the pulleys/belts, Alternator, and P/S pump, as well as the starter, and distributor plug wires and the carburetor was shrink wrapped pretty good so... He left it alone till I'm able to go see what all hes got!