383,440 and 400 compatability
09-18-2007, 09:35 PM
#1
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383,440 and 400 compatability
can you use 383 pistons and 440 magnum heads on 400 and what kind of performance increase and im looking at i know that the 383 had 440 magnum heads and that the 400 is just a 383 with a slightly bigger stroke so parts should interchange shouldnt they?
10-21-2007, 08:41 PM
#2
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depends on the year of your engines, i would look for pre 1974 heads, preferably casting numbers that end with 906, mic your pistons and cylinderrs to check compatability, why wouldnt you just buy new pistons? the 440 is the ticket, after all there is no replacement for displacement put you 440 crank in your 400 block and you have a 451 cid this can be done by grinding the 440 crank mains down to 400 size or grind out the 400 block mains to accomidate the 440 crank. shorter pistons are required for the shorter 400 block, makes a lot of power though. you can also make a 474 cid just an foffset grind job on the rod journals. hell you can turn that 400 block into a 496 cid if ya know what yer doin a have lots of $$$.
10-27-2007, 04:31 PM
#3
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I have 72 440 heads (with thw 906 at the end) and im going to buy new pistons but im unclear if I should go 440 or 383 I don't have a lot of 
and im teenager so im looking for no more than 350 at the fly so a stroker is out of the question maybe when I have more experience driving a muscle car ill get a bigger motor or go with a stroker but for now im sticking with what I have also im looking for the wheels that were in short circuit that were on the transam I havent been able to find anything out about them and im thoroughly stumped the good news through all this is my car has a solid body and the interior has already been redone im not sure what ill repaint it but that will be in the future for now ill worry about getting it runing and driving thanx for the help
and im teenager so im looking for no more than 350 at the fly so a stroker is out of the question maybe when I have more experience driving a muscle car ill get a bigger motor or go with a stroker but for now im sticking with what I have also im looking for the wheels that were in short circuit that were on the transam I havent been able to find anything out about them and im thoroughly stumped the good news through all this is my car has a solid body and the interior has already been redone im not sure what ill repaint it but that will be in the future for now ill worry about getting it runing and driving thanx for the help
10-31-2007, 12:42 PM
#4
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http://www.roadsters.com/wheels/ just thought I would share this with yall it has a lot of information on slotted mag wheels from american racing and hallibrand
11-05-2007, 02:49 PM
#5
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The short answer is no. 361, 383 and 400 are B blocks, 426 MW and 440 are RB blocks. 383 and 400 heads interchange, but it would be akin to puttin 318 heads on a 360 or vise-versa. The smaller chambers of 318 heads (higher compression) is negated by the smaller ports. In the case of 360, the reverse is true; the ports flow much better, but the combustion chambers are much larger than 318 and will drop compression on the 318. It ends up being a wash, performance-wise.
If it is a 400 you're building (correct?), and trying to do so on a budget, your best bet is to hone it and drop in some speed pro or KB hypers and just port the heads you have. Swapping cranks, decking blocks, milling manifolds and heads and all the other things that go into strokers and the like gets expensive quick. Shoot, just building Mopars gets expensive quick. The cost of building moderate street engines seems to run right about $10 or $12 per horsepower. Sometimes I wish I was a Chevy guy.
If it is a 400 you're building (correct?), and trying to do so on a budget, your best bet is to hone it and drop in some speed pro or KB hypers and just port the heads you have. Swapping cranks, decking blocks, milling manifolds and heads and all the other things that go into strokers and the like gets expensive quick. Shoot, just building Mopars gets expensive quick. The cost of building moderate street engines seems to run right about $10 or $12 per horsepower. Sometimes I wish I was a Chevy guy.
11-05-2007, 11:12 PM
#6
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the heads interchange I know they will because when the 383 hp engine was introduced it had the heads that would be used on the 440 super commando and like I said above the 383 was simply given a larger bore (sorry I got it backwards above) so if the 383 had 440 heads that means you can put 440 heads on a 400 its not rocket science its just common sense as far as keeping my stock heads and porting them id rather not the 440 heads give better performance than the open port 400s thanx for the info above though im still considering options and ill add yours to the list plus like I said above im not going with a stroker there to expensive and powerful at my age I meen im just getting my permit and I don't need to kill my self on my first ride
11-10-2007, 05:58 PM
#7
Big block heads should pretty much interchange, but there ARE some differences. Earlier heads, like the single 4BBL 426 and the "pre Roadrunner" 383 heads didn't have decent ports.
383's don't really have 440 heads, it's just that "they are the same." Speaking here of the 335hp 68 and later heads.
If you can find the rare 66-67 440 GTX heads, and I've forgotten the casting no. (907? 903?) you've got a rare pair.
HOWEVER--some of the later heads might be even better FOR YOUR application. This is because later "smog" heads, even though might have larger combustion chambers, and might be lower compression, have better valves and seats--for no lead fuel. This can be an advantage on a street car on pump gas.
The things that will NOT fit between 413/426/440s and the 383/ 400's is the intake, distributor, (I think) rods, pushrods, and without major mods, the crank.
383's don't really have 440 heads, it's just that "they are the same." Speaking here of the 335hp 68 and later heads.
If you can find the rare 66-67 440 GTX heads, and I've forgotten the casting no. (907? 903?) you've got a rare pair.
HOWEVER--some of the later heads might be even better FOR YOUR application. This is because later "smog" heads, even though might have larger combustion chambers, and might be lower compression, have better valves and seats--for no lead fuel. This can be an advantage on a street car on pump gas.
The things that will NOT fit between 413/426/440s and the 383/ 400's is the intake, distributor, (I think) rods, pushrods, and without major mods, the crank.
11-15-2007, 05:32 AM
#8
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ok so I mis enterpreted (sp?) what was written sorry for the confusion (and sorry for bein rude 66) so I should try and trade off my 72s for 73 to ? (need to find production years) 400 heads and rebuild them using Kbs and if I had the heads that came origanally with it I would use them but I don't also I ran across something the other day and it interested me the stock compression for a 70 440 was 9:7.1 with a pair of smog heads that run on unleaded that make the same comp. Could I run that compression ratio on the street or is the cut off 9:5.1 if so I may just fubar the 400 and go with a 440 hell I don't know I need to decide quick though the last thing I need is my mom getting po'ed because im not getting it running once again thanx for all the help
11-15-2007, 10:57 AM
#9
Damn, I wish you'd learn to type with good grammar. Your posts are hard to read.
Worrying about swapping 72 for 73 isn't going to gain anything
There was no such thing as a '70 with "smog heads"
Worrying about swapping 72 for 73 isn't going to gain anything
There was no such thing as a '70 with "smog heads"
12-30-2007, 06:56 PM
#10
Mopar Lover
about compression
ok so I mis enterpreted (sp?) what was written sorry for the confusion (and sorry for bein rude 66) so I should try and trade off my 72s for 73 to ? (need to find production years) 400 heads and rebuild them using Kbs and if I had the heads that came origanally with it I would use them but I don't also I ran across something the other day and it interested me the stock compression for a 70 440 was 9:7.1 with a pair of smog heads that run on unleaded that make the same comp. Could I run that compression ratio on the street or is the cut off 9:5.1 if so I may just fubar the 400 and go with a 440 hell I don't know I need to decide quick though the last thing I need is my mom getting po'ed because im not getting it running once again thanx for all the help
12-08-2012, 08:48 PM
#11
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the only diff between the b and rb is the deck height the rb is 3/4 of a inch taller your distributor and push rods are diff and your int a mag head has a smaller chamber compression witch bumps your compression up now if its just stock 440 heads no add on but 383 or 440 mag heads good choice
12-09-2012, 07:42 AM
#13
Mopar Lover
The short answer is no. 361, 383 and 400 are B blocks, 426 MW and 440 are RB blocks. 383 and 400 heads interchange, but it would be akin to puttin 318 heads on a 360 or vise-versa. The smaller chambers of 318 heads (higher compression) is negated by the smaller ports. In the case of 360, the reverse is true; the ports flow much better, but the combustion chambers are much larger than 318 and will drop compression on the 318. It ends up being a wash, performance-wise.
If it is a 400 you're building (correct?), and trying to do so on a budget, your best bet is to hone it and drop in some speed pro or KB hypers and just port the heads you have. Swapping cranks, decking blocks, milling manifolds and heads and all the other things that go into strokers and the like gets expensive quick. Shoot, just building Mopars gets expensive quick. The cost of building moderate street engines seems to run right about $10 or $12 per horsepower. Sometimes I wish I was a Chevy guy.
If it is a 400 you're building (correct?), and trying to do so on a budget, your best bet is to hone it and drop in some speed pro or KB hypers and just port the heads you have. Swapping cranks, decking blocks, milling manifolds and heads and all the other things that go into strokers and the like gets expensive quick. Shoot, just building Mopars gets expensive quick. The cost of building moderate street engines seems to run right about $10 or $12 per horsepower. Sometimes I wish I was a Chevy guy.
and as far as a chevy guy goes the parts are so plentiful and cheap because the chevy small blocks where so cheap that they needed stronger parts to compete at any serious level
mopar has very durable parts you can say the mopar parts and engineering is second to none in the big three!
all this stroking and aftermarket pistons is stupid.
for the street a 383 can turn 7000 grand all day long on factory parts, the classic hemi rods are tough as *****! and unless you can find a better deal on pistons to raise your compression stay with mopar. flat tops are fine
years from now when speed runner is older and has more experiences driving and more
flow he can go bonzi
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