Call LME and get a sick RHS440 that would be insane. You could as well upgrade the heads/block to use wider/thicker headstuds since youre running that much boost. The bigger motor will also drop the "boost" which should help avoid this problem then next time I guess.
RHS 427 - Whipple 4.0 - 2013 Black/Black ZL1 Manual
To follow this build like New Era Performance