Pinner58
New Member
- Aug 23, 2016
- 13
- Boat Info
- 1997 330 DA Sundancer, V-drivers,
- Engines
- 7.4 Mercruisers MPI Blue
Need help, 1997 Sundance with the 7.4 mercruiser engines. 454 big block. Have an exhaust leak. I first tried that metal patch, but filling in the worn area but still having exhaust leak. Thinking of changing out the cylinder head. First I was told that I just need to match up the six digit number under the value cover, which I did. The issue is the one currently on the engine has a cast number of CM6 and the used one I found has the same six numbers but has CM4. What's the difference? Can I replace the cylinder head that I have with one that has marking of CM4. Did anyone else come across this