Ok so had it all measured up properly, worked out closer to 8 thou of clearance, so god knows what the block was machined for before?? Anyway, I have had the Pistons measured and they are 91.257 (they have had about 2k of use) and having spoken to Mahle they recommend a 91.32mm bore size which is what I will get my spare block bored out to, that would give me 0.0026 inches, is this good for a 350bhp road car?

Regards, Kieren