I have never owned an S2K, always been a Bseries/EF/EK guy myself but I have recently taken a strong likeing to the AP1....takes a while but its gorowing on me, my question is...is the block closed or open like all the others? and how well do they work out boosted? any imput you guys have i would appreciate.

 

i think its an open deck, the internals are forged, i've seen 619whp stock block with a 3mm headgasket. so u can make some power on these stock blocks.