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I may be confusing a stroker "B" block that rebuilders crammed a 440 crank into, but I thought it had something to do with the shorter "B" rods in combo with the longer stroke "RB" crank create short dwell for the piston at TDC and BDC. Created even more low end torque than the already long stroke 440 crank. Of course short rods with long stroke also means smaller piston/ring space, more reciprocating stress, i.e. engines doesn't last as long unless you use better materials.

I think some of the variant performance engines Chrysler did, like the 440 Six Pack, had stronger cranks and were externally balanced with flywheels/dampers that were heavier at certain indexes. But for most of the engines that were made in big numbers, they were well balanced.

And yes, when I rebuilt my 440, I went with aluminum pistons, but had all the components balanced, I was shocked to find out the aluminum pistons were heavier than the stock steel pistons and they had to add metal to the crank to balance it. So yes, I see the comment about how lots of people rebuilding Mopar Big Blocks made mistakes and had a poorly balanced engine.
 

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The original appeal of the 400 block was its larger bore.

After folks started installing 440 crank's in 400 blocks in became obvious the 400 block was stronger.

A side benefit was the smaller main journals, a 440 crank needed the mains ground to fit.

This made previously worthless worn out 440 cranks useable again.

Strange how what was once considered a dud became desirable!!

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Randy
 

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The original appeal of the 400 block was its larger bore.

After folks started installing 440 crank's in 400 blocks in became obvious the 400 block was stronger.

A side benefit was the smaller main journals, a 440 crank needed the mains ground to fit.

This made previously worthless worn out 440 cranks useable again.

Strange how what was once considered a dud became desirable!!

Thanks
Randy
Yep, its coming back to me now, get a worn out 440 crank cheap, have it cut down and install it in your 400 rebuild, for something like a 464? But like I was saying, cut down crank with shorter rods, you had to limit the rpm's and it would wear faster. But because of the short dwell at TDC/BDC and greater bore, it was low rpm torque monster to snap your neck at stop lights for around the town driving.
 

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The "stroker" combo keeps the stock rod length and custom pistons with shorter deck height.

Actually works out better overall.

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Randy
 

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As a side note when I built the Engine in my wagon I used a 4.15" MP crank in a 440 block.

"Stroker" pistons weren't available at the time so I used 429 Ford pistons!!

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Randy
 

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The "stroker" combo keeps the stock rod length and custom pistons with shorter deck height.

Actually works out better overall.

Thanks
Randy
Works out better for low end Torque/Power.

But my understanding, and that was the reason why Chrysler went with a raised deck block to stroke the "B" block, is the engine is going to have a shorter life.

At the same time, if you're doing a custom rebuild of "B" block, and you invest in high quality chrome molly rings, better alloy custom pistons, finer machining of the bores, etc, I guess you could offset that wear to be no worse than most most engines.
 

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I may be confusing a stroker "B" block that rebuilders crammed a 440 crank into, but I thought it had something to do with the shorter "B" rods in combo with the longer stroke "RB" crank create short dwell for the piston at TDC and BDC. Created even more low end torque than the already long stroke 440 crank. Of course short rods with long stroke also means smaller piston/ring space, more reciprocating stress, i.e. engines doesn't last as long unless you use better materials.

I think some of the variant performance engines Chrysler did, like the 440 Six Pack, had stronger cranks and were externally balanced with flywheels/dampers that were heavier at certain indexes. But for most of the engines that were made in big numbers, they were well balanced.

And yes, when I rebuilt my 440, I went with aluminum pistons, but had all the components balanced, I was shocked to find out the aluminum pistons were heavier than the stock steel pistons and they had to add metal to the crank to balance it. So yes, I see the comment about how lots of people rebuilding Mopar Big Blocks made mistakes and had a poorly balanced engine.
I know this is from a few years ago, but I was surprised nobody called you out about steel pistons!
Stock pistons are all cast aluminum.
Most performance pistons are either forged aluminum or just a better alloy than stock.
NO pistons are steel.
Steve
 

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He probably meant to say steel strut cast aluminum pistons.

Cast pistons have a steel strut cast within to control expansion.

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Randy
 

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To further pile on the necro-post:
If one wants to make a valid comparison between 383 and 400 you have to start with 1971 specifications (the only year Chrysler published both gross and net horsepower numbers).
383-2: 275 gross hp, 190 net hp
383-4: 300 gross hp, 250 net hp
Compare the NET numbers above to the 1972 400 specifications:
400-2: 190 hp
400-4: 255 hp
Compression in 1971 was 8.5:1, in 1972 8.2:1. So the decrease in compression was offset by the increase in displacement. In other words, by the time of transition from 383 to 400 they were pretty evenly matched.
 
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As a side bar to this 383-440 conversation. I owned a 1965 Plymouth Sport Fury or my parents and I owned it. With all the Mopars I have owned over these many years, this one is the one I wish I had today. It was so very different than most.
Bench seats (younger generation no console) great make-out car.
Hurst floor shifter that bent over the seats for a short stroke gear change
383 Commando engine 330HP Torque 425 FT-LB 4-barrel Carter carb
Crank windows No a/c RWD
Non leather seats, not cloth they had not gotten around to calling it vinyl yet. Baby blue with dark blue seats
Front vent windows Carpet front and rear
Hand adjusted outside mirrors Fender skirts Rim look wheel covers not spinners as pictured
AM radio 8 track player no clock after market radio reverberation unit ( look it was a thing back then)
This was a big heavy car that would move. To use an expression from back then "It would haul the mail"!
L 209.4" W 78" H 54.9" WB 119" Curb Weight 4,045 lbs
Pictures not my car but this is how it looked. Please feel free to correct if I remembered wrong.
79181
79182
10371862-1965-plymouth-sport-fury-std-c.jpg 2872992226_76c073f807_z.jpg
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1963-plymouth-belvedere-golden-commando-1.jpg
 
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