Tell a 383 from a 440

[Yeye]

Hi there,

As far as i know, B and RB blocks are very similar, is there any reliable method to tell from these pictures whether it's a 383 or a 440 ?

Please note i won't be able to reach the car before one month as it is currently sailing to Europe.

 

[detmatt]

Near impossible to tell from those pics with that ac b.s. In the way.

 

[traintech55]

Two ways, but not so easy. One a "RB" block will have a raised pad by the distributor, while a "B" block will not. The one I like to use is the casting number on the left side of the block, the first three numbers will tell you the engine displacement ex 4002714 = 400 cu.in.

 

[Yeye]

Yes, this can be done once the car is here, pictures won't help...

 

[saylor]

do you have pics of any tags/vin etc? it looks pretty original..we can decode it maybe

 

[Yeye]

Yes, that's what i think too, either the swap is very old, or the seller is wrong (thus the engine should be the original one).

 

[Snotty]

I am sure you know that a 383 is narrower than a 440, but only the best-trained eye is going to be able to tell from these shots. As has been said, look for the raised boss behind the AC compressor.

Here is a similar view of the 440 in my '70 Newport. You can't really tell anything from it.

 

[Fury440]

I am sure you know that a 383 is narrower than a 440, but only the best-trained eye is going to be able to tell from these shots.

How so, the heads and intake manifolds are interchangeable. Maybe you mean the 440 block is taller than the 383?

 

[Yeye]

0.38" more stroke...

 

[Polara_500]

How so, the heads and intake manifolds are interchangeable. Maybe you mean the 440 block is taller than the 383?

Heads are interchangeable, yes - intake manifolds, not so much. RB's are wider so the manifold has to be also.

 

[Fury440]

Heads are interchangeable, yes - intake manifolds, not so much. RB's are wider so the manifold has to be also.

You are right, the heads are higher up the "V" which makes them further apart.

 

[Snotty]

How so, the heads and intake manifolds are interchangeable. Maybe you mean the 440 block is taller than the 383?

383 intake manifold on a 440 will fall between the heads - will not fit as it is too narrow. Neither will the distributor. That's why when someone swaps a 440/rb where a 383/b used to sit, they also have to swaps some of the external mounts, like AC brackets, etc.

 

[Fury440]

383 intake manifold on a 440 will fall between the heads - will not fit as it is too narrow. Neither will the distributor. That's why when someone swaps a 440/rb where a 383/b used to sit, they also have to swaps some of the external mounts, like AC brackets, etc.

True, I wrote without thinking it through.

 

[70_NPORT]

....if you've seen enough 383 and 440 engines in cars you can tell by the width difference of the two blocks. The 440 will be wider between the valve covers than the 383. Its not much, but its there...takes a trained eye, lol.

 

[tallhair]

it is difficult to tell with the A/C in the way and the rest of the stuff there.

When it get's to Europe ... take of the air cleaner and see what the part number is on the intake and it will either be a B or RB intake.

Or get down under it and look up at the engine casign number

or look behind the power steering and look at the engine here

383 / 400 B

RB 413 / 426 / 440

Same thing on other side

The RB or Raised Block is higher ... see red circles

or maybe you can see this casting flash behind the power steering

 

[Snotty]

i

or maybe you can see this casting flash behind the power steering

View attachment 75491

It's easier than all of that; just look for the raised pad to the right of the distributor mount. It's in your picture here. That's what I look for.

Also, the size of the motor will be stamped on that pad if it's there, as well as the letter code telling what year the motor is.

That pad is not on a "B" motor - 350, 361, 383 (except for first two years), and the 400. It is on all "RB motors, 413, 426 (wedge and hemi), and the 440. You can see it clearly on the motor in this picture, just look to the right of the distributor hold-down clamp:

This will be behind your AC compressor, but it will be easy to see once you look behind the compressor, if it's there.

 

[tallhair]

It's easier than all of that; just look for the raised pad to the right of the distributor mount. It's in your picture here. That's what I look for.

Also, the size of the motor will be stamped on that pad if it's there, as well as the letter code telling what year the motor is.

That pad is not on a "B" motor - 350, 361, 383 (except for first two years), and the 400. It is on all "RB motors, 413, 426 (wedge and hemi), and the 440. You can see it clearly on the motor in this picture, just look to the right of the distributor hold-down clamp:
View attachment 75501
This will be behind your AC compressor, but it will be easy to see once you look behind the compressor, if it's there.

yes in my pictures but he'll definitely not be able to see those in his pictures

 

[Big_John]

As far as i know, B and RB blocks are very similar, is there any reliable method to tell from these pictures whether it's a 383 or a 440 ?

No.

 

[Yeye]

yes in my pictures but he'll definitely not be able to see those in his pictures

Yes, everyone here seems to agree...so, i'll be waiting until the car reaches europe's ground...

 

[Yeye]

Good afternoon america !
The car has landed in Europe, it's a 440 4bbl from 1973 in it, according to the intake manifold casting number (3689444).

Will post pictures soon, but i would be ashamed not to clean the car prior