the block has 4.44 bore which is normal.it has billet steel main caps,enforcement material in lifter valley which is kind of yellow and extremely smooth.material of the block isn`t grey it`s more like stainless by the colour.everything is enforced and my bowtie looks like standard block in comparison.i of course bought it.it was in a alky engine at 526 cid making 1400 hp.(measured).what can this be.pictures can be found at www.nastytoy.se (http://www.nastytoy.se)

well after hours of reading and research it`s a cnc mark 4 bowtie.those 8620 billet maincaps distracted me at first.

this seems to be my own topic.i managed to get castnumber at last:10051107.early siamesed pro stock bowtie block with billet main caps and supposed to have 4.5 max bore.if the block is siamesed can`t it be bored bigger? i bored a marine block 4.47 ans it wasn`t siamesed.the combo dynoed 1400 hp in which the block was.any additional info would be great.