The downside of the 601/602/603 is that the heads coolant ports were not originally drilled out from factory. Anyone with one of these engines that has pulled the head should have noticed the lack of coolant ports on the head. the block is equipped with the ports. This can lead to lack of coolant flow.

What we do:

I carefully use my jig to mark the correct locations to drill the new coolant ports into the head, I then de-burr the ports and flush the head to clean the shavings.

Requirements:

The head needs to be stripped and preferably deep cleaned, an additional $100 fee will be charged for me to deep clean the head myself.