I just had my 350 sonic tested and one side of the cylinder is thicker than the other, it's not a perfect circle. The oil vally side and the freeze plug side #8 cylinder I think. I planned on making this motor a 383 w/ 450hp but if i can't I'll keep the 350.
My question is: Can this engine still be rebuilt? What hp and torque numbers can I make with this?

Don't know as you didn't post the thickness numbers :noway:

I think the oil vally side is .212 and the freeze plug side is .235. I can get the numbers on Monday. Just looking for an idea, hopefully this engine can be built.
Thanks

69,
It is pretty normal for one side to be thicker than the other. In a perfect world, the walls would be the same thickness all around, but on stock blocks it is pretty rare. The thrust side ( passenger side) of the cylinder is the most important.

What if the thrust side is off? Does that mean the block is junk?

Depends on the actual thickness. And no, it is not junk, but it might not be usable for the horsepower level you want. The other thing to think about is, if you have to buy pistons anyway, get them in the smallest oversize than the bores will clean up to. Post the actual thicknesses, top and bottom thrust and non thrust for all 8 cylinders, or at least the best and worst, then you can get some meaningful answers.

I think the oil vally side is .212 and the freeze plug side is .235. I can get the numbers on Monday. Just looking for an idea, hopefully this engine can be built.
Thanks

Those are great numbers for a 350 block. I tend to concern myself with the front and back dimensions, the thinnest you'll find where the cyls are closest to one another. I like to see a minimum of .125" there for most applications, but that isn't always possible. For 450 HP a .030" overbore is fine in most situations, you're only removing .015" per side, and with wear it's even less than that.

This engine from a 70 impala 300hp 4 bolt main. The block hasn't been butchered. It has no warping or visiable cracks.

It's nice to have the thrust side thicker when core shifts are noticed.

The machine shop told me today the cylinder walls are to thin (front to back) and the block has many core shifts. So the verdict is... the block is junk.