To help cool the engine I decided to make use of the supplemental cooling ports that were in the RPM Air-Gap manifold. When you connect the rear 3/8" ports forward to the 1/2" ports you create an additional cooling path for the block. T

his also helps "wash out" any trapped air or steam into the coolant expansion tank. I made the connections with Russel Pro-Flex and Endura 8AN fittings.