4.3’s are confusing

[1987sylvanoffshore]

Ok serial # F370508 1995 4.3LX GenII 4 barrel
I want confirm from my research this is the 205hp non Vortec non roller cam motor. I’m considering purchasing this motor if the compression test checks out. So here are my 3 questions. 1-What compression #’s should I be looking for.
2- My blown motor has a mechanical fuel pump, this one is the electric fuel pump. Would the power for the fuel pump be in my current wiring harness or am I going to need to run power to it some other way.
3- is this motor 205 hp with the 4 barrel carb?

My boat is a 1989 Starcraft Islander 261V. Thanks!

 

[Rick Stephens]

You pretty much have it figured. The '95 is pre-vortec. Most of them did not even have the mechanical fuel pump port in the block. Your motor also is balance shaft. Should be no problem dropping in the '89.

Power for the fuel pump is taken from the same purple wire that goes to the electric choke. Same circuit, Y'd off to a oil pressure switch then to the pump. The starter should also have a lug on the outside that is connected to the fuel pump power wire.

 

[Scott Danforth]

compression numbers for any stock 4.3, 5.0, 5.7, etc. are between 150 and 155 when the motor is new.

any compression numbers below 120 mean that the engine will soon need a rebuild

any compression numbers below 100 means that the engine may or may not run and needs to be rebuilg

any compression numbers over 155 mean that your gauge is off, or you have water or oil in the combustion chamber

the 4.3 Vortec (1996 and later) was rated at 220hp prop with MPI (240 crank HP) it would have about 205-210 HP with a 4-barrel (225 crank HP). the 1995 and older motors with the non-vortec heads would be about 15-20hp less.

with the 4.3's get a complete bobtail when swapping, or stay within the family generation.

 

[QBhoy]

I’d think a pre vortec would be labelled as 190hp.
as said. Most engines this age had the electric pump with the thinking dome by the oil pressure. Just swap it all over I’d say. Great engines.
150-160 would be a new engine reading as far as I know. Truth be told, most cheap gauges will read as much as 20/30 psi off the mark without being calibrated.