Early 400 C.I. "superblocks"

[RTDaddy]

These blocks called super blocks due to thicker web at the main bearings? Curious what defines a "superblock."

 

[YY1]

440source (makers of stroker kits) has a detailed writeup.

With pictures.

 

[rickseeman]

These blocks called super blocks due to thicker web at the main bearings? Curious what defines a "superblock."

Yes, massively thick main webs. 383 vs 400

 

[rickseeman]

These are commonly called "230" blocks. Because that's the last 3 digits of the casting number. But not all 230 blocks have these heavy mains.

 

[RTDaddy]

Thanks guys, gotta go drop a pan now.

 

[rickseeman]

What is the casting date?

 

[rickseeman]

If there is a piston out you can see it from there.

 

[RemCharger]

Here is a 383 block I disassembled, at speed. It was about 600+ stock stroke, quite alot of runs on it. I still think the crank gave up first, but we'll never know. The 383 before that one had MANY runs at the 600+ level, and some with 275 packed on top. That block lived well, but separated a rod and did damage.
There doesn't appear to be much material there...

 

[RTDaddy]

What is the casting date?

Barely legible, but "71."