B and RB

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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aerodynamic
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B and RB

Post by aerodynamic » Thu Dec 13, 2007 11:28 am

What are the physical differences between the B and RB blocks? What's interchangeable and what isn't?
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Post by 71GTX » Thu Dec 13, 2007 1:21 pm

I am only going from memory here...

The RB blocks are the 413, 426 wedge and the 440. The RB is commonly called the "Raised Block"; RB

B Blocks are your 361, 383, 400....

heads are interchangeable

Crank?? not sure, length of stroke may be different on each....

Rods?? Not sure

Intakes are only interchangeable with the designated block....you cannot put a RB intake on a B block motor or vice versa
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Post by 71440 gtx » Thu Dec 13, 2007 3:38 pm

B Blocks are 350 361 383 400

rb
413 w 426 w 413 mw 426 mw 440 426 hemi

and a 1959 rb 383 4.030 and a stroke of 3.750 inches

the mw heads will not fit on the low block 383. 413w 426w the mw heads have 2.08 1.88 62-64 413 mw blocks are notched for the heads and the other blocks are not, so they will not fit. :beer: but they will fit a 440 because the bore is bigger.
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Post by aerodynamic » Fri Dec 14, 2007 6:35 pm

Thanks guys
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Post by 71GTX » Thu Dec 20, 2007 8:27 pm

It's a fine line between a hobby & mental illness!

69 RoadRunner (clone)
70 Cuda 383 4 speed (project)
70 Cuda convertible 340 4 speed (project)
70 Barracuda (project)
71 GTX 440 4 speed (project)
72 Cuda 340 3 speed (project)

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Post by mopar71 » Thu Dec 20, 2007 11:30 pm

Thanks 71gtx,great info,I double checked all my parts and all match. Engine block,exhaust manifolds,intake. 8)
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Post by 71GTX » Fri Dec 21, 2007 5:38 pm

I just picked up a 69 383 HP block w/extras for my one of my dads cars and found that link last night while researching a set of heads that came along with the package....
It's a fine line between a hobby & mental illness!

69 RoadRunner (clone)
70 Cuda 383 4 speed (project)
70 Cuda convertible 340 4 speed (project)
70 Barracuda (project)
71 GTX 440 4 speed (project)
72 Cuda 340 3 speed (project)

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