95 Merc 260 to a Vortec

[party barge]

I guess my first post was a bit much but I been thinking today about a repower. I have a 95 mechanical fuel pump flat tappett motor now and if i repower I would like more power. Is it easier to just go to a Vortec 96 and up or use a more agressive cam in my rebuild of what I got. What changes have to take place for a Vortec swap from a 260? thanks

 

[95yj]

Re: 95 Merc 260 to a Vortec

If you're buying a complete new motor, then swapping in a Vortec EFI is a piece of cake. You'll have to spend about $300 to put in an electric fuel pump kit with all the wiring, etc. to be USCG legal. If you're doing a long block, then you have to consider that your intake manifold is different and your timing advance on the distributor is also different, plus wiring changes, etc. Lastly, if you're running an Alpha one outdrive, the max rating is about 300HP and that is pushing it, so putting in a 5.7L EFI vortec that may be rated at around 320HP may or may not be a bad thing. Full throttle takeoffs will definetly cause problems.

I just did this swap myself on my '97 22.5 Express Cruiser and decided to stick with the carburated non Vortec 5.7L longblock. YMMV

 

[John_S]

Re: 95 Merc 260 to a Vortec

A vortec long bock should be a rather easy swap for your '95. Just because it says "vortec", it may not be an '88 or newer block. Make sure any long-block you are considering, is. Go with a carbed 4brl and you will have about 280hp at prop. You can find the long-blocks with flat or roller cams. No significant hp difference, but roller cam is less prone to lobe wear. Generally, if it has a roller cam, it will have a fuel pump block-off and will require an electric fuel pump set-up. Otherwise, you need a special fuel pump push rod to work with steel roller cam. Your distributer should have the GM "melonized" gear, which is compatable with both the GM flat and roller cams. Since a long block may use an aftermarket cam, check with suppier on distributer gear requirement and fuel pump. If you get a long-block with composite timing cover, you will need a marine water pump that clears it (assuming raw water cooled).