1988 4.3 Mercruiser

[kellerr1]

I'm restoring a 1988 30' Larson. It has twin 4.3 MerCruisers. One has what I think was the head gasket go. Can I replace it with any 205 HP 4.3 mercruiser? The boat seemed a little under powered and the other engine is now showing low oil pressure? I have put a ton of work into the interior and don't want 10K if junk fiberglass.

 

[Bt Doctur]

replace both with 5.7s

 

[bman440440]

I believe in 1988 the 4.3's where rated at 175 HP... if you get 1997+ 4.3 LXH's they where 220 HP... they had 4bbl carb's and vortec heads... or like said above drop a couple of 5.7's in there and be done... IMO that is what I would do in your case with a 30' boat and you will prob get better mileage because you will not be working your engines as hard... summit has them (part #HME-VMH4) for $2300 complete long block... you can use your risers and just get new exhaust manifolds and a few other parts and you are good to go with 75+ HP and loads more torque!

 

[Watermann]

You could move over all your current 4,3 set up with your parts if you stay with that same year of replacement 4.3 long block. You would have to spend a ton of money to change over to 5.7's, all the tin, manifolds, distributors, ignitions including a different gear ratio for your drives.

 

[Scott Danforth]

take your motors to a machine shop. swap the pistons out for D-shaped dished pistons and install vortec heads (1996 and later) with screw in rocker studs, a vortec intake and a 4 barrel carb. then transfer over your marine stuff on it. you will have about 220hp and it will cost you well under $2k each motor

 

[Watermann]

You'll need new intake manifolds if you go to the vortec heads.