Inquiry was raised during cyl head replacement on 12V4000M90 5262000224/5 of cylinder head supersession chain. Some clarification was needed as there are two separate supersession chains for 4000-01 marine heads, only difference being alternate ...
There was a difference in the base head part # which was due to a supplier change for the head casting. The exhaust valve part # is different though MTU confirmed “parts are 1:1 exchangeable”. There was the change in part number because the supplier ...