When we had the new motor (383sbc) on the run in stand it would not come up to temp and got condensation in the valve covers. Checking cyl. head temps the rear was running hotter than the front. We are using a Magna Flow and a 4X2 Air Gap. My engine builder would like to plumb from the two top rear ports on the Air Gap to a 1" spacer under the T-stat and also use a T-stat as we will be in cold river water alot of the time. Anyone have any ideas on this?