- Jul 10, 2020
- 161
- Boat Info
- 1981 310 Vanguard Express
- Engines
- Twin Mercruiser 6.2 MPI Horizon FWC inboards
Hi - going deep here.
I have Mercruiser MX MPI 6.2 Horizon engines, 2004, with closed cooling. Serial number is OM317xxxx (I forget the exact number but the 317 is one important break and I'm after that).
For reasons detailed in another thread ("Rocky buildup") I may need replacement heads, though I am hopeful a valve job will be enough. If I do need replacement heads, I am not entirely sure which to get.
I believe I have 906 Chevy Vortec heads. I know the exhaust valve is 1.5" diameter so I think that means they are not specifically 062 heads. So some questions:
- Can I use remanufactured Vortec heads from a 350 (5.7)? Same heads as my 377 I think.
- Do I have to get "GM Marine"? As far as I can tell, that just means stainless steel valves. (Compare this one and this one.)
- It seems like a lot of the road Vortec-head engines have flat hydraulic lifters; my engine has roller hydraulic lifters. Am I right in thinking that doesn't matter when selecting a head?
- Most of the listings are "1996-2002" fitment, I know my engine is an '04 but I think 96-02 is the right generation of Vortec. Am I right there?
- I see this, a remanufactured 906 head at a decent price. It seems to be the right one. Other than exhaust valve size (make sure it's 1.5" not 1.6") what else do I need to check?
Thanks!
I have Mercruiser MX MPI 6.2 Horizon engines, 2004, with closed cooling. Serial number is OM317xxxx (I forget the exact number but the 317 is one important break and I'm after that).
For reasons detailed in another thread ("Rocky buildup") I may need replacement heads, though I am hopeful a valve job will be enough. If I do need replacement heads, I am not entirely sure which to get.
I believe I have 906 Chevy Vortec heads. I know the exhaust valve is 1.5" diameter so I think that means they are not specifically 062 heads. So some questions:
- Can I use remanufactured Vortec heads from a 350 (5.7)? Same heads as my 377 I think.
- Do I have to get "GM Marine"? As far as I can tell, that just means stainless steel valves. (Compare this one and this one.)
- It seems like a lot of the road Vortec-head engines have flat hydraulic lifters; my engine has roller hydraulic lifters. Am I right in thinking that doesn't matter when selecting a head?
- Most of the listings are "1996-2002" fitment, I know my engine is an '04 but I think 96-02 is the right generation of Vortec. Am I right there?
- I see this, a remanufactured 906 head at a decent price. It seems to be the right one. Other than exhaust valve size (make sure it's 1.5" not 1.6") what else do I need to check?
Thanks!
