260 Mercruiser engine blocks

party barge

Cadet
Joined
Aug 14, 2007
Messages
25
Mine is a 95 260 Mercruiser, it has a mechanical fuel pump, 1 piece rear main, all cast 2 bolt main and roller compatible. Does anyone know the origination of this block with GM? Someone told me Caddy Fleetwood from 93 to 96 was this engine but the yard has a 95 there but no fuel pump pad. I wanna parts engine. thanks:D
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: 260 Mercruiser engine blocks


You need a pick up truck engine......;)
 

riverjet502

Petty Officer 2nd Class
Joined
Dec 28, 2006
Messages
116
Re: 260 Mercruiser engine blocks

There is no magical "marine" block"... A engine block is an engine block.. Just look for 1 with a one piece rear main seal. No fuel pump pad? No problem use an electric marine fuel pump such as a Mallory. Reason people say go truck block is gennerally they will have the more desirable 4 bolt mains. A 2 bolt main block will due just fine unless you are seaking 6,000 rpm plus, for extended durations. Then you would want forged internals as well as the 4 bolt main.
 

FreeBeeTony

Captain
Joined
May 15, 2002
Messages
3,991
Re: 260 Mercruiser engine blocks

Think the reason truck blocks/engines are more desirable is because the cam is very close to a marine cam.........not because they are 4-bolt.
 

party barge

Cadet
Joined
Aug 14, 2007
Messages
25
Re: 260 Mercruiser engine blocks

I was told once that GM made the blocks for Mercruiser and added more nickel to them for corrosion protection. I noticed that with this engine of mine that it does not rust inside an actual rust color but a black color instead. I stick my finger in the hole and wipe and all I get is black, no scaling at all and all the deck edges are sharp still....weird

Any way, I know about truck stuff...I was just wondering if this was all true about GM produced blocks for Mercruiser or if Mercruiser choose blocks that GM used in cars and trucks. I'm not concerned about fuel pumps just the fact that a 1 piece rear main block has not been found with a mechanical pump provision anywhere in our yards here or Jeggs. Ya can't get anything near close from a place like Jeggs in a crate form...seems Mercruiser had all these ends tied well.
 

riverjet502

Petty Officer 2nd Class
Joined
Dec 28, 2006
Messages
116
Re: 260 Mercruiser engine blocks

Yep bought a lot of stuff from Jeggs & summit over the years... I wouldn't sweet the block if it has no boss for a mechanical pump. You would be just fine with a Mallory 4110M electric pump. Crate engines.. There's a thought. I know alot of guys that run jet sprint boats that run the snot out of the ZZ4 350 right out of the crate. It's either off or wide open. Tough little small block for the money...
 

Haut Medoc

Supreme Mariner
Joined
Jun 29, 2004
Messages
10,645
Re: 260 Mercruiser engine blocks

Wrong one.....
You need one piece....
Never mind.....:redface:
 
Top