Designed for 4.125" bore applications this head is 
designed to flow tons of air through the mid-lifts.
Using a 2.080"intake valve with a 235cc port volume 
we have achieved LS-7 type flow numbers from .3-.5.
This head also incorporates a new 86cc exhaust port
that uses a 1.600" valve designed for larger cubic 
inch applications. Combustion chamber comes standard
at 70cc.
Note:Minimum recommended bore size is 4.030"