Hi Big Dad
Your post is from some while back, but I am looking for a solution to similiar problem. After some searching I found out that my GM671 is fitted with a reverse gear clutch from Auto...

Dear people
I am on a loss, so I hope for answers here. I have a Detroit Diesel/Gray Marine 671. Looking at the block, it clearly is a 671 (from my comparison with internet pics), but the number...

Dear jgmo
Many thanks for your swift reply. I will start a new thread. I am in contact with MTU as well.
Thanks
Adrian.

Dear people
I am on a loss, so I hope for answers here. I have a Detroit Diesel, named Grey Marine 671. Looking at the block, it clearly is a 671, but the number stamped in the block does not agree...