4.3 TBI to Vortec

Thanks for the add to the group... fairly new boat owner.

First boat... 1991 Reinell Sunchaser 192
180 hours on the meter
All original and super clean
Mercruiser 4.3

Purchased it, used it 1 summer, and a buddy came to help me winterize it because "he knows how to do it right"

He didn't.

Broke block.

Found another 4.3 with OMC stuff. Bought it, swapped all the parts, and put it in... fires right up and purrs like a kitten. Ran it for 10-15 minutes to set timing, etc... and shut it off. Next day, pull dipstick, and there is about 2 gallons of water in the pan. Boo...

So I found a rebuilt 4.3 marine longblock for a great deal... but it has Vortec heads.

Is there any benefit to spending the $$ to buy the different manifold and keeping the Vortec heads, or is it better just to swap my good TBI heads off of my first engine onto the new block and call it a day??

Any advice would be appreciated, and thanks in advance!!!

 

Are u running carb.. throttle body injection.. or multi port injection.. vortec is just a valve passage design in the head itself that increases flow and fuel atomization by making a swirling effect as the air and fuel travel thru the valve runners. ... all types of intakes are made for vortec heads. . But if your looking for the most efficient and by far the safest means of fuel delivery.... go with multiport injection.... if that is what your asking... vortec is only head design. Its hard to determine which intakes you have from the info you have given

 

vortec is most efficent... but it could be a head problem. And swapping heads may only transfer your problem to the new block

 

I am running a 2bbl carb with TBI heads

I guess I was really trying to figure out if it was worth it to buy a Vortec long block, and then have to buy the conversion intake, etc... to make it all work.


I ended up picking up a rebuilt 4.3 today that has the same TBI heads than I do. From some research any difference in HP between the TBI heads and the Vortec heads would be small enough that I would probably never notice the difference...