Broken Main Cap...Information needed

Never seen this before, engine confirmed never apart, so probably happend upon initial assembly in 86-87. Engine is from an 87 CSX, and because of numbers matching I need to use this block. I don't have another early block to rob a cap from, all of my spares are TIII. I do have an 86 2.5 tall block I can use but not sure if the caps are the same? I thought this engine was the precursor to the common block, so I don't know if the caps are interchangeable. I am aware of the requirement for line honing once the swap is done, I just need to know if I can source the cap from the tall block or not.

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looks like the broken one is still working just fine.

Yeah....I don't think I would line hone over that, especially if you are not pushing the limits. I would say the most important part of that broken piece is to center the cap and you can accomplish the same thing by being very very careful during assembly.

I ran it on a neural network empirical finite element analysis setup (i.e. the corner of my brain devoted to "She'll be right" judgements. ) and concluded same as above, doesn't look like it contributes much at all to running strength, just makes alignment easier in assembly.

I think if you were really pushing the block then it would be an issue allowing the cap to walk that direction. Is it possible to weld it back on :P
If your cap is walking around then I would say the fasteners were not doing their job so you are already in a bit of a pickle.

If I were that deep in the motor and could put my hand on a broken part it would go in the dumpster. replace and line hone is the only way I would trust a motor.

This engine has been stock all its life and not really abused other than the ravages of time and mileage. My nephew owns it and since I am doing the maintenance (he is learning) I get to dictate its boost level and usage. My machinist looked at the pix and said no problem, add some weld to the edge of the cap and machine back to the correct register dimension. This is good, because it saves me some worry and effort in putting this thing back together.

Thanks for all of the opinions, for information sake, does anyone know if the 86 tallblock caps are the same as the 2.2 caps. I haven't compared them to the common block caps I have laying around, so maybe I can answer my own question?

Just adding on some weld sounds like a good plan and probably easier to pull off than reattaching.

Tall deck should work, its a CB or as you said, early one. They use CB cranks.