Can't find 1992 Mercruiser 4.3 Pre-Vortex intake manifold

[nic420]

Has 12 bolts. Can't find replacement. Any suggestions?

 

[Lou C]

I've found a few on ebay.

 

[nic420]

Looking for GM 14097289 intake manifold. I looked at the the ones on ebay but they are used.

 

[Lou C]

That’s all that you’re going to find, they probably haven’t been made in years. Other option is an Edelbrock aluminum intake.

 

[Scott06]

4.3L - 4 bbl. V6 Edelbrock Performer 90° Intake Manifold (1985-95) - Michigan Motorz

Chevrolet 90° V6 intake manifold. PERFORMER 90° V6 (idle-5500 rpm) Designed for street 1985-95, 200-229-262 c.i.d. (3.8 & 4.3L) Chevy V6's. Will not...

www.michiganmotorz.com

this is not a brass lined cross over so won’t work if you are in salt and raw water cooled

 

[Lou C]

They make a brass lined version, check their site.
Used cast iron ones can work perfectly well as long as the water passage isn’t cracked. Usually all you have to do is clean up the sealing surfaces. Try to get one from sellers in the Midwest fresh water regions.

 

[nic420]

Thank you Lou. My currently has a Rochester 2 barrels. I was afraid to by the one you recommend without knowing the carb i have to switch to. Do you know which carb I should get to match?

 

[Scott Danforth]

any 1995 and older intake will fit your 1992 motor without balance shaft.
since you have to buy a new manifold....
I would update the heads to vortec and run this manifold

Performer Vortec V6 Marine Intake Manifold for GM 90 Deg V6 (4.3L)

Edelbrock Marine Vortec V6 4.3 Intake Manifold for Chevy 4.3L V6 Marine Engines w/Vortec Style Cylinder Heads. Cooling Water Passages are Lined with Brass to Prevent Corrosion. Accepts Q-jet or 4150-Style Square-Bore Marine Carbs. Non-EGR

www.edelbrock.com

 

[nic420]

I also noticed the distributor might have to be replaced too? I'll give them a call to ask. Thanks again Lou.

 

[nic420]

I was thinking about upgrade too, and now thanks to you, I know what to get.

 

[Scott Danforth]

I also noticed the distributor might have to be replaced too? I'll give them a call to ask. Thanks again Lou.

why?

 

[Scott Danforth]

I was thinking about upgrade too, and now thanks to you, I know what to get.

I would do a threaded rocker stud conversion (the pressed in studs sometimes pull out) and run adjustable rockers. generally not needed, however that is my preference.

I also like to remove the casting flash on the exhaust ports and combustion chamber prior to bolting the heads on. again, generally not needed, however frees up about another 7-10hp.

 

[Lou C]

No need to replace the distributor; the Vortec heads are a nice upgrade if yours needs head work anyway. I bought two 4.3 cast iron 4bbl intakes from eBay and they were both in good shape. Still using my original that’s been used in salt water 15+ seasons. I think filling the engine with good antifreeze at winterization helped it last this long...

 

[Lou C]

Thank you Lou. My currently has a Rochester 2 barrels. I was afraid to by the one you recommend without knowing the carb i have to switch to. Do you know which carb I should get to match?

Well that depends on what you want to do. If you want to add about 20 hp or so go with an Edelbrock 1409. If you’re happy with the performance of the 2 bbl and want to save money then I’d think about a used 2bbl cast intake from eBay or places like NLA marine parts. What’s wrong with the original intake?

 

[nic420]

why?

My current distributor is the drop in type w/o mounting holes.

 

[nic420]

The OG intake has a crack at the 1 in plug by the stat housing. I cracked it while trying to remove the plug during the engine rebuild.

 

[nic420]

The crack is very small and hair line thin. I was wondering if it can be welded?

 

[Lou C]

Find a good automotive machine shop and ask them.

 

[nic420]

JB Weld it?

 

[Scott Danforth]

My current distributor is the drop in type w/o mounting holes.

they all are.