What carburetor to use on a 4.3 GM V6 Vortec

[i-am-steve]

I'm planning to replace the (ruined) GM 4.3 V6 engine in my 1987 Four Winns 19 ft boat. I think I have identified a donor vehicle at the local salvage yard -- a 2002 GMC Sonoma. I understand I would need to install a different intake manifold to convert the engine to a carbureted setup. Specifically, I plan to use an Edelbrock 2114 manifold.

My question is, what carburetor would be appropriate for this setup? I am thinking perhaps an Edelbrock 1409, but that is just a guess based on no actual knowledge.

Other things I think I will need to deal with in this project:
- switch to an electric fuel pump
- change accessory belt system from v-belt to serpentine/ribbed belt
- possibly a different flywheel (something to do with a one-piece vs. two-piece seal?)

Thanks for any input.

 

[Scott06]

You're right on the money here. The 1409 is a great fit. If your serach posts here Rick Stephens posted his jetting changes to work on a 4.3 vortec.
Fuel pump accessories and flywheel are different. I believe the bigger flywheel dictates a different coupler and starter. If your old ignition is points you may want to upgrade to later Tbolt V or Delco unit.

 

[Bondo]

Ayuh,.... The 1409 is a carbon copy of the Merc/ Weber carb that comes from Merc on that motor,....

The electric fuel pump is no biggie, just wire it through an oil pressure switch, for 1 leg, 'n off the outer tiny terminal on the starter's solenoid for the startin' leg,....

Both motors are 1 pc rear main seals, but the newer motor most likely is balanced differently,...
You'll need a standard shift flywheel that's For the newer motor,...

Why not go with the v-belt,..?? you've got the pulleys, 'n accessories from the old motor,...

 

[Scott Danforth]

You also need newer style motor mounts with the balance shafted 4.3 vs your non balance shafted '87

 

[achris]

You ignition system is TB-IV, and should just drop into the new engine.

 

[i-am-steve]

I picked up a 2002 4.3 V6 from the salvage yard today. It came with the power steering pump. If I want to use the serpentine belt setup, I think I would just need to convert my (almost new) alternator. I think the main reason I'd go serpentine is because of the nifty automatic belt tensioner.

A friend has a new/unused Holley R84023-3 model 4010 marine carburetor he'll sell me at a reasonable price. I think it may work, but I'm not too sure how to evaluate that. The Holley web site shows that it is 600CFM. Any opinions on that instead of the Edelbrock 1409?

Regarding the motor mounts -- why would it be necessary to replace them? The old ones are presumably meant to absorb more vibration, but if the new motor produces less vibration, that does not hurt anything, right? Would the mounts affect the alignment with the outdrive somehow? Just trying to understand.

 

[Scott06]

If you use the edelbrock which is a copy of the factory Weber carb Mercruiser used you can buy throttle bracket Mercruiser part # 805359T and the throttle linkage will be a bolt up. Also if you have the slave solenoid and circuit breaker mounted to the throttle bracket these will bolt up as well.

Don't have experince with the engine mounts but your comment makes sense

 

[Scott Danforth]

I picked up a 2002 4.3 V6 from the salvage yard today. It came with the power steering pump. If I want to use the serpentine belt setup, I think I would just need to convert my (almost new) alternator. I think the main reason I'd go serpentine is because of the nifty automatic belt tensioner.

A friend has a new/unused Holley R84023-3 model 4010 marine carburetor he'll sell me at a reasonable price. I think it may work, but I'm not too sure how to evaluate that. The Holley web site shows that it is 600CFM. Any opinions on that instead of the Edelbrock 1409?

Regarding the motor mounts -- why would it be necessary to replace them? The old ones are presumably meant to absorb more vibration, but if the new motor produces less vibration, that does not hurt anything, right? Would the mounts affect the alignment with the outdrive somehow? Just trying to understand.

Most automotive accessory drives have the power steering pump mounted low....needs to be mounted high in the boat so the system bleeds (pump above actuator)

You need to use a marine circulation pump

Both the holley and edelbrock 1409 are 600 cfm

Dont forget the marine head gaskets and brass core plugs