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Teach me please! 906 heads

Steve009

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hi everyone,

I'm looking to learn about these 906 heads I have on my 383. The block is from a 64 Plymouth but he heads are off a 68 roadrunner I believe. Here is the question and what I am looking into. Are the 906 heads the same for both 440 and 383? I heard you can interchange heads on these engines but I was curious if 440 and 383 have different "906" heads (please excuse my ignorance if it's a stupid question). The reason I ask is because I am looking into fenderwell headers for my 64 sport fury and dougs has a awesome set for 440/426 wedge. On the website they mention it fits both 906 and 915 heads. Under the section for 383s they don't offer these headers. Can anyone clarify if the 440 (906 heads) headers would fit my 383 with 906 heads?

https://shop.dougsheaders.com/doug-...65-metallic-ceramic-coating.html#.WEhe87TEif0

Thanks!
 
Yes
The 906 heads are the same for the 383/440
A very good performance head

(In 2001 I sent a set in to Indy Head and had them mildly re-worked)
NOTE: This is when Indy Head was good....

The headers fit
 
Yes
The 906 heads are the same for the 383/440
A very good performance head

(In 2001 I sent a set in to Indy Head and had them mildly re-worked)
NOTE: This is when Indy Head was good....

The headers fit

So the geometry of the 383 versus the 440 block won't change if the headers will fit (440 is wider I think)? With these headers in particular one tube swoops under the k frame and if the angle is off I'm worried it won't fit properly.
 
Maybe contact Dougs to be sure. Do you have to use those headers, or are you just going for the look? Hedman, Dougs, and TTI make under chassis headers.
 
I've seen header manufacturers state, for B and RB engines. I would think if a header is made for a RB and you used it on a B engine some clearance issues might come into play and with the opposite. Some header manufacturers don't specify between the two.

I just measured a B engine and a RB, across the width of the engine, from where the header would bolt up to the heads.

The B engine measures 20 inches across.
The RB engine measures 21 inches across.
The difference of 1 inch total overall.

The deck height of a RB is 10.725
The deck height of a B is 9.98
The difference of .745 almost 3/4 of an inch.
 
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Hmm, YUMMY!
Fender-well headers!
Also:
The 383 RB and the 440, the 906s were the same/same head.
Point being: If you order headers tell them you have a 383 OR a 440

And, many Header companies will state: fits 383 RB/440

Again the answer is YES
 
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Maybe contact Dougs to be sure. Do you have to use those headers, or are you just going for the look? Hedman, Dougs, and TTI make under chassis headers.

I'm looking for fenderwell headers in particular for the "bob mosher superstock" look but I'm open on brand choices. I'm going to call Dougs but just wanted to see if anyone here had experience with it.
 
I've seen header manufacturers state, for B and RB engines. I would think if a header is made for a RB and you used it on a B engine some clearance issues might come into play and with the opposite. Some header manufacturers don't specify between the two.

I just measured a B engine and a RB, across the width of the engine, from where the header would bolt up to the heads.

The B engine measures 20 inches across.
The RB engine measures 21 inches across.
The difference of 1 inch total overall.

The deck height of a RB is 10.725
The deck height of a B is 9.98
The difference of .745 almost 3/4 of an inch.

Thanks for taking the time to check and do the measurements! I think I'll have to have a convo with Doug's to see if they have ever dealt with this. I'm not too worried about the three going through the fender well but it's the one tube going under that bothers me.
 
Steve, here ya go:
Mosher's 63
This is the look I am going for on my 63 Polara
Dale Reed built my engine, he does all of Bob Mosher's (I helped)

Mosher 63.jpg
 
Steve, here ya go:
Mosher's 63
This is the look I am going for on my 63 Polara
Dale Reed built my engine, he does all of Bob Mosher's (I helped)

View attachment 377511

Thats so badass! One day I'll sell the 64 Plymouth HT and get a 63 or 62 dodge sedan. Or maybe if life goes well I'll buy both haha (lottery fingers crossed)
 
a 440 with a taller deck will locate the exhaust port in a different location than a 383. the 440 exhaust ports will sit higher and further apart in the chassis vs a 383.
 
a 440 with a taller deck will locate the exhaust port in a different location than a 383. the 440 exhaust ports will sit higher and further apart in the chassis vs a 383.

This is interesting and what I thought may happen. I'll have to see what kind of spacing around the k frame the headers leave and if that difference will still allow it to fit in my application.
 
This is interesting and what I thought may happen. I'll have to see what kind of spacing around the k frame the headers leave and if that difference will still allow it to fit in my application.
there are some headers out there that won't fit both engines when used in the same chassis. ask the mfg questions before buying. a 2" header may not be ideal for a 383. 2" headers aren't always the best choice for a 440.
 
there are some headers out there that won't fit both engines when used in the same chassis. ask the mfg questions before buying. a 2" header may not be ideal for a 383. 2" headers aren't always the best choice for a 440.
X2 Lew, the Hedman headers on my 63 with a 383 were listed as fitting RB motors not B motors and required some clearancing to fit the chassis with a 383.
 
X2 Lew, the Hedman headers on my 63 with a 383 were listed as fitting RB motors not B motors and required some clearancing to fit the chassis with a 383.

Are we talking cutting pipes or just slight bends/tweaks? What model number of Hedman did you use?
 
Are we talking cutting pipes or just slight bends/tweaks? What model number of Hedman did you use?
Most of the time, it's dents....which doesn't seem to hurt but does look crappy.
 
there could be an issue with a tall deck header on a low deck engine hitting the steering shaft. there's always the issue with fenderwell headers and the tires. a friend had a set of hedmans, that only had one tube exiting the fenderwells, and he had to create some kind of steering stop to keep from blowing front tires,..lol. nobody that i know of makes fenderwell headers anymore for a reason. they were a crude solution to a problem. back in the early '60's most headers were hand fabbed from pieces of tube and going out the side was the easiest solution. with the advent of computerized tube benders all those issues became obsolete.
 
I called Dougs and the guy I spoke with didn't know much. Apparently their R&D guy will call me next week to discuss.
 
These are Hedman 78036 which are listed as fitting an RB motor but to use in a B motor on a 63 requires some denting but no cutting. If you have a choice find something to fit rather than trying to install a header then pulling it out, some hammer massaging then see how it fits and multiple in and outs. Just my 2 cents worth. Good luck.
 
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