RB VS B Blocks

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MoparMuscleGuy

MoparMuscleGuy

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Does an RB block have more value and is it more desired than a B block? Just curious as to your opinions. Thank you MMG
 
most guys building a serious race motor want the 400 ci B block, but they are close in price 440/426w 413 to a 400, 383 worth the least of the "popular" blocks
 
I have 440's and a couple 400's and I have researched and if you would have asked me 10 years ago I would have said 440 but knowing what I do know about 400's and Strokers It is definately 400 for me, I just dropped off a 72 400 block and a 72 440 steel crank to my machinist to hot tank and start on my journey to 451 Stroker land! Shorter deck equals stronger more rigid block, less height less flex, 400 has the biggest bore of ANY big block Mopar, so as much as I love saying "440" I will have to say 400 block!
 
Same same. If it has "HP" stamped on it it's worth a little more strictly due to hype. Otherwise, it's worth what someone's willing to pay.
 
I guess there is a difference in the crank part # though.
I wonder what the difference is if any?????
I have a 1973 hp 400ci engine but have not cracked it open yet.



Big Block Mopar Crankshaft Part #'s
Part# Engine Material Comments
2268114 383 4BBL Forged
3462922 383 / 400 2BBL Cast Externally Balanced
3672000 400 4BBL Cast Premium Cast Crank<<<<<<<:evil3:
Suitable for mild hop-ups
2536983 67-71 440 4BBL Forged A good general crankshaft
3512036 70-72 440 6BBL Forged Externally balanced
premium crank
3671283 72-73 440 4BBL Forged A good general crankshaft
3671242 73 440 4BBL Forged Balanced for different
weight pistons
3751889 74 440 2&4 BBL Cast Externally balanced
3751899 74 440 HiPo Forged A good general crankshaft
2406240 413/426 Max Wedge Forged Best RB crankshaft
 
T67POWER said:
I guess there is a difference in the crank though.


Big Block Mopar Crankshaft Part #'s
Part# Engine Material Comments
2268114 383 4BBL Forged
3462922 383 / 400 2BBL Cast Externally Balanced
3672000 400 4BBL Cast Premium Cast Crank<<<<<<<:evil3:
Suitable for mild hop-ups
2536983 67-71 440 4BBL Forged A good general crankshaft
3512036 70-72 440 6BBL Forged Externally balanced
premium crank
3671283 72-73 440 4BBL Forged A good general crankshaft
3671242 73 440 4BBL Forged Balanced for different
weight pistons
3751889 74 440 2&4 BBL Cast Externally balanced
3751899 74 440 HiPo Forged A good general crankshaft
2406240 413/426 Max Wedge Forged Best RB crankshaft
Click to expand...

No not really, "factory" 400's used cast cranks and back in those days it was either cast or forged (there wasn't different grades you could choose from) I'm not aware of being able to order your 440 or later on your 400 with a extra special crank. Back in those days if you were building 400HP or lower use cast (remember these are old world cast cranks) everything over 400 use forged. With few exceptions forged cranks are internally balanced and cast externally balanced. The 440 6 pak crank required an external balancer because of the heavier con rods, more or less. Nowadays you can buy basic quality forged cranks and top of line forged cranks but I believe it's not necessarily the steel involved but more the process, quality control and testing at the molecular level which seperates a good quality crank from a top quality crank. That and price of course.

Now they do list a forged crank for the 400 in 71-72 cars but guess what, it's actually the 383 forged crank or what was left over when the 383 was discontinued in 71-72.
 
LOL! yeah don't wanna make some of those guys sick when they realized they paid WAY!!! too much for a block stamped HP!!!!:mrgreen:
 
kid, it's unfortunate that most people don't bother trying to learn the truth. You can't learn when you already know it all. You'd be surprised how many people waste money only because of that feeling. It's not that others don't try....
 
056 kid said:
Cool, mopar fans that like watching other mopar fans waste money. I can think of a few words that describe that kind of person well :knob:
Click to expand...

Sometimes people only learn after they've wasted there money, this even after members here have told them "don't do it it's a waste of money". Some people don't listen to reason, some people don't listen at all. Which one are you 056 kid, a listener or a know it all. I couldn't care less either way, most likely just a flash in the pan.
 
Demon seed....
I listed the part # for you to read as it says there is a premium cast crank in the four barrel engines.
I have not looked at the crank and how it's machined on my 400 hp engine but since it carry's a different part # i would think it may have something to do with the grade of quality and or how it's been manufactured.
 
T67POWER said:
Demon seed....
I listed the part # for you to read as it says there is a premium cast crank in the four barrel engines.
I have not looked at the crank and how it's machined on my 400 hp engine but since it carry's a different part # i would think it may have something to do with the grade of quality and or how it's been manufactured.
Click to expand...

I have no idea why they would call it "premium" but I doubt it is because of the actual grade of cast iron (carbon content being the big kicker). It could be something as simple as slightly larger oil transfer holes or a wider filet area on the throws and crank journals or even a slight change to the snout. Any change to the original crank will cause a new casting number to be generated which is the norm. Because these cranks were massed produced by casting companies I'd be willing to bet that the same actual cast iron for the premium crank and stock crank came out of the same molten oven that day. Whether the "premium" cast iron crank actually turns out to be more durable or stronger or less prone to harmonics only an engineer of the day would be able to answer that question. But wait for it, there's enough talent on this forum we may have one of these people waiting to jump in on the discussion.
 
demon seed said:
Sometimes people only learn after they've wasted there money, this even after members here have told them "don't do it it's a waste of money". Some people don't listen to reason, some people don't listen at all. Which one are you 056 kid, a listener or a know it all. I couldn't care less either way, most likely just a flash in the pan.
Click to expand...

i have been an observer all my life. . .

As for a flash in the pan. . Naa.
 

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I can stamp an HP on a 440 block, weeeeee


The block cost should be based on bore size, std or not and how big, aside from that...the next thing to consider is the casting, some casting do have thicker/wider webbing than others.

Go look at 440 source and their info and PICS of the differences.

Non hemi/non 426 max wedge blocks should go for around $100-$250 bucks depending on the area/availability/bore size/condition, if there are no yards to pick from this can be capitalized on of corse....

Then there r some are looking to make a fortune off of you and charge $300-400, pass them up.
 
I won't pay over $100 for a standard bore block, B or RB.. unless the seller can show me the block has been sonic checked or includes something in the deal that i can resell to get my money back. I've been burned once before, never again.
 
After talking to Dan Dvorack, we pulled the pan on a 69 block casting, stamped 71 hp. The hp puts those heavy as hell 6 pack rods in it.
 
i just read in that there is TWO 383 motors. a B block and RB block. when was the RB 383 made? it has a 4.030 bore and3.750 stroke compared to the B 383 with a 4.250 bore and 3.380 stroke. weird. and yes the 400 4 barrels had "better" cranks. i only have 2 4 barrel cranks or else i would visually compare. the book says better casting under notes for 400 4 barrel cranks, yet says suitable for mild hop ups. everything else ive read says cast cranks can handle ALOT in these others yet the "better" 4 barrel states only good for mild hop ups? fiiiiishy
 
for big power stroker applications I'll take a 400 over a 440 any day. Love my RB's but B's hold up better in high HP applications. Shorter block means stiffer cylinders plus look at the meat where the crank sets to the cylinder wall on the RB's versus the B blocks...
 
The RB 383's were made in, as I recall, '59 and '60.
 
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