Mopar 400 block ID help pls

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Brooks James

Brooks James

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T7 400 1st row
10-5-2. 2nd row Oct 10 1972 ??
E. 3rd row

Block casting last three 230
 
doug 371 said:
pretty sure it is
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Ive read that the 230 block was from 71-73, and that the 71 are higher nickle content, and that 71-72 had the thick cylinders capable of an .0080 over bore
For me it's the holy grail
 
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It's the correct casting number, but not all of them were the same. You need to post pictures of the main saddles so those in the know can see. Also the outside sides of the block I believe, too.
 
RustyRatRod said:
It's the correct casting number, but not all of them were the same. You need to post pictures of the main saddles so those in the know can see. Also the outside sides of the block I believe, too.
Click to expand...
Picking the motor up next weekend, then tear it down
 
.080 over?????


Lol, never going to happen.

The difference in the 400 blocks is in the main webbing. Problem is 400 blocks have issues with thin cylinder walls long before the main webbing becomes an issue.

Where do you guys read this stuff lol?

I went through (4) 400 blocks to find a good one for overboring 4.375".
 
When going to 4.375 overbore , how much cyl. wall thickness is acceptable to you ? Say if I were to sonic check a std. bore 400 block, what number would I look for to be good for that overbore ? Thanks
 
EdsWelding said:
When going to 4.375 overbore , how much cyl. wall thickness is acceptable to you ? Say if I were to sonic check a std. bore 400 block, what number would I look for to be good for that overbore ? Thanks
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Unknown at this point, maybe some one will chime in
 
Better yet, with that overbore size how much thickness is needed on the thrust side for the block to live at say 650-700 HP, filled of coarse ! Thanks
 
Jeremiah said:
.080 over?????


Lol, never going to happen.

The difference in the 400 blocks is in the main webbing. Problem is 400 blocks have issues with thin cylinder walls long before the main webbing becomes an issue.

Where do you guys read this stuff lol?

I went through (4) 400 blocks to find a good one for overboring 4.375".
Click to expand...

Exactly. When you find the "holy Grail" block and it needs 6 sleeves. More like the Holy Money Pit.
 
The thing to do is don't worry about a particular bore size. Clean it up at the smallest bore possible. Trying to make power by boring is stupid, because it makes such a small amount of difference.
 
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