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383 B Block, 440 heads, Dazed and Confused

iveshrugged

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OK, so I picked up what was supposed to be a 440 RB complete motor with 727 out of a mid-70's motor home chassis. However, once I was able to run the numbers from the purchase, I didn't have a 440, I had a 383, specifically:
Casting No. 2468130-11, date stamped Mar 1970. So, that's not bad, a 1970 383, should be 9.5:1 compression, factory specs says 330hp, so I can use this somewhere, someday.

Now, this is where it gets weird, I went and looked up the intake and heads, cause the seller was sure it was a 440. Well, the intake and heads are as follows:

Intake Casting No. 3830949 - 400 4bbl intake, 75-76 production date
Heads Casting No. 3751213 - (2.08/1.74) 1973 400/440 motor home heads

I'm open to any opinions here. Not sure what I got, but I got it super cheap. Lemme know what you think.

Block Casting No.jpg Block Casting Date.jpg Intake Casting No.jpg Head Casting No.jpg
 
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should say 440 or 383 in casting no. on side of block, also 440 has flat id pad on top next to dist hole , 383 has id pad straight under dist on block by head gasket surface.
 
The B and RB engines use the same heads so you are ok. The intake if cast as you say is for a 440 only and won’t fit on a 383. 383 and 400 can only be used on a 361, 383 or 400 block because both are low deck blocks where as the 440 intake can be used on RB blocks such as the 413, 426 wedge and 440.
 
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OK, so I picked up what was supposed to be a 440 RB complete motor with 727 out of a mid-70's motor home chassis. However, once I was able to run the numbers from the purchase, I didn't have a 440, I had a 383, specifically:
Casting No. 2468130-11, date stamped Mar 1970. So, that's not bad, a 1970 383, should be 9.5:1 compression, 4bbl Carter carb, etc, factory says 330hp, can use this somewhere, someday.
Now, this is where it gets weird, I went and looked up the intake and heads, cause the seller was sure it was a 440. Well, the intake and heads are as follows:
Heads Casting No. 3751213 (2.08/1.74) 1973 production date, 400/440 heads
Intake Casting No. 38394975-76 440 4bbl intake, 1976 production date

I'm open to any opinions here. Not sure what I got, but I got it super cheap. Lemme know what you think.

View attachment 1264028 View attachment 1264029 View attachment 1264030 View attachment 1264031
Is this intake actually bolted on? I would like to see pictures. The only way it could and that.s if it can be done the intake and heads would have to have about 5/8 milled off.
 
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I don’t have one to look at, but doing a search shows many listings of that number being sold as a 400 piece.

https://www.forcbodiesonly.com/mopa...ead-bore-intake-3830949-75-southern-md.50151/

I think we’ll agree that the OP’s block casting number is clearly a 383....... and the manifold appears to be bolted down.
If that’s the case...... it’s obviously not a 440 manifold.

View attachment 1264521 View attachment 1264522
I agree. Makes no sense. Typical post that the poster does not follow through on. Good, bad or ugly.
 
I agree. Makes no sense. Typical post that the poster does not follow through on. Good, bad or ugly.
"poster does not follow through on." What does that mean??? What else do you want me to do??? I'm open to suggestions. Heck, I posted pics, I posted casting numbers, I did the research and clearly state I'm aware the heads are 440 heads from a motorhome, I clearly state the intake is a "400" intake, I never stated it was for a 440. Not sure why you'd reply like a jerk, but I'm all ears. Enlighten me, what exactly am I supposed to "follow through on"???? I'll wait patiently for your reply
 
"poster does not follow through on." What does that mean??? What else do you want me to do??? I'm open to suggestions. Heck, I posted pics, I posted casting numbers, I did the research and clearly state I'm aware the heads are 440 heads from a motorhome, I clearly state the intake is a "400" intake, I never stated it was for a 440. Not sure why you'd reply like a jerk, but I'm all ears. Enlighten me, what exactly am I supposed to "follow through on"???? I'll wait patiently for your reply
See, this is why newer wrenchers and weekend home-garage warriors are reluctant to post anything on these forums, because of trolls. Newer guys to this game are just looking for some positive advice, some direction, from others with more experience and wisdom, and what do we get, smartass comments.
 
Calm down.
@pnora usually has solid advice he's very knowledgeable and usually pretty helpful, maybe he had a bad day or something, yes he was unfairly harsh.
Sorry but I can't comment on the heads but it looks like the intake is for a spreadbore so it would likely have had a ThermoQuad (which is pretty cool).
It looks like you have some condition issues. I'm guessing it's locked up.
You'll need to pull the heads and see how bad the bores are.
It may be a project just to disassemble but a 70 would have a forged crank.
Some overall pictures would be helpful.
 
Looks like you have an older 383 block with newer year style heads and intake. Take a picture of the ID pad which should be under the distributor hole as that can tell us more than the block casting.
That block would have had 906 heads and somebody switched them out to what you have now. Pretty much all big block heads will fit B block ( 361-383-400 ) or RB block ( 413-426-440 ) so no mystery there.
The intakes is where a difference is, B block intakes will not fit RB blocks as they aren't wide enough and RB intakes are too wide to fit B blocks.
The crank should be a forged internally balanced one. Picture of the dampener would determine internal or external balanced.
Forged cranks are better than cast but not a deal breaker as they are both good for street use.
Upload some more pictures and we can give you a clearer picture of what you have.
 
"poster does not follow through on." What does that mean??? What else do you want me to do??? I'm open to suggestions. Heck, I posted pics, I posted casting numbers, I did the research and clearly state I'm aware the heads are 440 heads from a motorhome, I clearly state the intake is a "400" intake, I never stated it was for a 440. Not sure why you'd reply like a jerk, but I'm all ears. Enlighten me, what exactly am I supposed to "follow through on"???? I'll wait patiently for your reply
You originally said this. And now it is edited to say 400. [[[[ Intake Casting No. 38394975-76 440 4bbl intake, 1976 production date]]]] When you stated it was a 440 intake on a low deck. Lots of people come here and post an issue and never reply again. At least now you know what you have and there is no issues.
 
See, this is why newer wrenchers and weekend home-garage warriors are reluctant to post anything on these forums, because of trolls. Newer guys to this game are just looking for some positive advice, some direction, from others with more experience and wisdom, and what do we get, smartass comments.

welcome to fbbo.....take a deep breath....... you won't find a better. more helpful group of people than there are on this site...... don't make me sic my dog on you
 
1st off welcome , and like eldubb posted this is the best mopar sight or for that matter car sight on line you will find.
Tons of info on here along with good advice.
The search link up top right will bring you info on damn near anything mopar.
Pretty much everyone on here will help out when they can.
Good news is you have a big block mopar with pistons up near the deck .
Get the heads off and see what you got.
:thumbsup:
 
It's all good depending on what you want to do.
You will not have 9.5:1 compression. Just the way it is, and you heads don't add to it. Needs cleaned partially disassembled and inspected. Can run well just needs parts.
 
To the OP:
What you likely have is the result of a motor home engine that was transplanted, maybe due to overheat or crank/rod bearing issues. The engine would appear to have been replaced with a 383 shortblock, the original 440 heads reinstalled (may refute the overheat option), and a 400 intake (possibly because the shop/person doing the repairs didn't know the intake manifolds were different and found out the hard way, or maybe they knew all along) To my knowledge (yep my 1st post, so one could assume I know nothing, it'd be an incorrect assumption, but a fair assumption) motor homes received only 225/6, 318, 360, 413 & 440; but I'm unaware of any 383 powered units.
Depending on the year, the class A (large units) used truck (med duty) heads with coolant passages in the front of the heads and a unique water pump.
So you don't have a 440, but the 383 can be stroked to 426 fairly easily, or they really were an underdog that could surprise many street race outcomes.
 
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