[Tinker]

with the head off take a long screw driver or/and coat hanger and clean out the back of the block. between rust and casting sand the rear of the block suffers.



Think about a river flow, the pumps are up front and the coolant intake and exit is up front of the block. Where would be a weak spot for sentiment? ....Center outlets don't help much either.


Now if you had room you can flip the heads and draw fliud out the rear of the engine. But like the L head we have limitations.


cleaning the rear of the block will help wonders.