[Dominik]

I agree on seasoned blocks for ultra-high horsepower engines.
Here you want to avoid that any tolerances shift during a race after the block has been machined.

As stated earlier 1,5l 1.000hp... So once you aim to produce 5.000hp from your 450+ cui you want a seasoned block. Of course, I exaggerate a bit, but you get the picture.

Also, I wouldn't know if aluminium shifts as bad as cast iron under racing use.

I would buy a new block.

Dom