Bottom end of thick main 400 block

[v8440]

Hi all,

Before I left town for Atlanta today I stopped by the machine shop and took some pictures of the 400 block I recently found. Those of you familiar with what the main webbing of most big block chryslers looks like will no doubt notice a difference.

 

[Foggy]

A nice stout piece to begin with.:dance:

 

[Yokmoni]

Is that a truck block and what year is it?

 

[v8440]

No, it's out of a '72 newport. It was a 400 2 bbl. The story on these blocks is this: '72 model year 400's had a casting number ending or beginning (I can't remember which) with the numbers "230". The casting number on these blocks is in taller numerals than most other big block chryslers. The earlier blocks had the thick mains. The casting date range I've read is from April 4, 1971 to October 10, 1971. Mine was cast on June 3, 1971. Most of the '72 400's were cast too late to get the thick mains. This is my 4th '72 model 400 block-I have three that have regular mains because they were cast too late. All 4 of the ones I have show the same casting number, so that can't be used to determine which set of mains it has.

Note that I've said nothing about what the block came from in this. That's because it does not matter-casting date is the only criteria that determines which main webbing style it gets.

 

[69.5CUDA]

sure looks alot like my 413 block

 

[v8440]

Is yours an industrial 413? I have a '64 413 block, one of the type that came in either a truck or a max wedge motor. I wonder if it has really thick mains like that? I suspect not-the 440source.com article on blocks probably would have mentioned that if they did.

 

[69.5CUDA]

ya know i have no clue what its from just that its a fairly clean block with only some surface rust on it.....ive never looked at the #'s on it

 

[BB71Challenger]

No, it's out of a '72 newport. It was a 400 2 bbl. The story on these blocks is this: '72 model year 400's had a casting number ending or beginning (I can't remember which) with the numbers "230". The casting number on these blocks is in taller numerals than most other big block chryslers. The earlier blocks had the thick mains. The casting date range I've read is from April 4, 1971 to October 10, 1971. Mine was cast on June 3, 1971. Most of the '72 400's were cast too late to get the thick mains. This is my 4th '72 model 400 block-I have three that have regular mains because they were cast too late. All 4 of the ones I have show the same casting number, so that can't be used to determine which set of mains it has.

Note that I've said nothing about what the block came from in this. That's because it does not matter-casting date is the only criteria that determines which main webbing style it gets.

Is it an automatic that the block has thicker mains if the build date is within the dates you gave? I just looked at the 400 I had in my Challenger and its build date is 7-21-71. Would be nice to have a block with that thick of main webbing.

 

[v8440]

As far as I know, yes, it is a given that blocks cast in that date range have the thick mains. Yours does indeed fall into the range, so it should have them.