Wow John,
that sounds awesome. A +600ccm is crazy! Is it a V12 engine? Darton is a good choice. I like them...
We used sleeves for a Peugot disesel engine. They are cheap... My goal was to build a stronger block, not more displacement.
Yes, it's the V12 from the 550 Maranello, so I guess I'll have to change the name to a 600 Maranello The car is staying naturally aspirated, and its stock rating is only 88 HP/liter, so it's not stressed at all. The new 458 Ferrari has some insane HP/Liter figure around 110 or 115, so it's far more stressed than this '12.
Mine is a heavy GT class car, meant for comfortable, high speed cruising, not a hotrod like the 458.