Mercruiser 5.7 model year and HP?

[tfmech]

Serial number is M680411 supposed 260hp 350. Anybody have the actual year and hp. That and when I go order parts like cam and stuff for it what is the actual engine family designation for it?

 

[Scott Danforth]

On a small block.....the three things you need to know with an SBC are is it a 1-pc or 2-pc rear main seal, does it have vortec heads (8 bolts on intake vs 12) and does it have a roller cam vs a flat tappet. That last one is ehat you need to look into. If the intake has 8 bolts, it most likely has a roller cam and a 1 piece rear main.

If the valve covers have perimeter bolts, you most likely have a 2 piece RMS and you have non-vortec heads.

Most importantly, what is the block casting number.

 

[alldodge]

The serial number on the Merc site is after 2001 and shows roller cam, roller cam and should be 250HP for carb, 260HP for EFI and 300HP for MPI as my guess. Fun Times would be able to bring up the data

 

[Scott Danforth]

If its EFI, you will need to reflash the ECM if you play with the cam.

if its carb'd your limited to a cam such as http://www.compperformancegroupstor...CC&Product_Code=12-417-8&Category_Code=RFHRXM unless you go with a different exhaust

 

[tfmech]

It's non EFI has a high-rise aluminum intake on it and original q jet

 

[tfmech]

That was the cam I was looking at, it has aftermarket exhaust but still has shorter risers the mix about a foot back I think that 270 should sound good