Chevy & GMC Vans

ok, I'm posting this for my neighbor that is looking to replace the motor in his boat. I really know nothing about boats and what'll work or won't..

all he's asked me to post is: what are the differences (if any) between the two motors, 92 4.3L and 94 4.3L Vortec. he mentioned mounts, bell housings etc

I think his boat already has the 92 but he's looking to purchase/rebuild the 94 and install it in place of the 92 (if it'll work)

any and all input is appreciated

rob

I am pretty sure he has to get a Marine engine, as a car engine "turns the wrong way". At least that is what I have always heard.

Have him check out sterndrive.com

afsigma21 wrote:I am pretty sure he has to get a Marine engine, as a car engine "turns the wrong way". At least that is what I have always heard.

Have him check out sterndrive.com

X2

I have a 4.3 in my boat.
It looks to be the same as an astro 4.3.
As long as its a standard rotation engine.
Marine engines use stainless steel head gaskets and have better cams.
Basically though, they are are the same design.
starting in 1996, GM changed the heads to true Vortec, and they mount an intake differently, so those would give him grief, unless he gets an 8 hole manifold.
From 85 to 95, GM produced the VIN Z type engines which do not have an internal (BS) balancer shaft.
However, from 92 to 95 GM also produced the VIN W which do have internal BS.
92-95 heads flow a bit better than the pre 92 heads, but they all will bolt to any 4.3 block, even a 2005.
The bellhouse mount points do not change either.

Anyways for 85 to 95 engines, You can visually determine if it has a Balance Shaft By the timing gear cover style.
if it looks round on the top, exactly like a SBC 305 or 350, its a non BS engine.
If it is either a plastic or tin cover that is quite a bit taller and pointier than the usual SBC cover, its full of BS.
But, you know either way, both blocks could bolt up to his intake and exhaust systems and bellhousings just fine.
I just put a 95 BS engine into an 87 no BS van. I found out the OMC flywheel is the same as the astro/S10 flywheel.
I have an astro 4bbl manifold on my OMC.
Anyways, there are differences but you can be sure it will come together with some thought.

Here , this guy can explain it way better than I and he can be found all over the net.
http://www.marineengine.com/boat-forum/ ... 1d70ffed2f

thank you thank you thank you... lol.. I'll pass all this great info along to him =D>

I have found old boats to be a good source of big block engines. I have used 2 of them in hotrods over the years.
Other than the aformentioned parts, the only other differences I have found between a marine engine and an automotive engine is the oil pump and pan, the exhaust manifolds and some times the bracketry on the front of the motor might be different.
As best as I can remember they have all turned in the same direction. :-k

Peter