Post by
C-Kwik »
https://forums.nicoclub.com/c-kwik-u426.html
Fri Jul 11, 2008 8:18 am
Sleeving the block in that of itself doesn't affect the cooling passages. Bracing or closing the deck can affect , but when power levels get high enough, it becomes necessary. Open deck blocks have a tendency to have the cylinders shift under high pressure, which can cause problems with head gasket sealing.
I'm not sure at what power levels that becomes necessary at, but I would check with some people who are experienced with building a high HP VQ. Bear in mind, if any more power could be in order later on, now would be the best time to do such work, rather than to have to pull the motor apart again.