Stromberg WWC carb

[redone76]

@rvrrun
@SBMech
@rivermobster
My buddy picked up a ‘66 GMC 2500 with the 401cu V6 engine. It runs good but had some seepage from the carb gaskets. I’m going to go thru it for him and I noticed on the back of the carb there is 2 holes in the throttle blade plate that goes into the venturi’s. So it’s taking in unfiltered air? Is this normal for these carbs? Should I block them off somehow? It’s the stock carb for this truck. If anyone else has experience with these carbs please chime in! Thanks for letting me pick your brains!

Sent from my iPhone using Tapatalk

 

[SBMech]

You sure they pull vacuum? Usually there is a BB in that passage if I remember right. Or it's blocked by the gasket?

Let me consult my ancient text....

 

[SBMech]

I don't think it's open to atmosphere. Here's a breakdown in case you need some reference material.

 

[rvrrun]

That was an old dealer trick to improve hot starting. It won't hurt to plug them and get it running smoother if you don't have the hot starting problem (which you might with ethanol).

 

[redone76]

You sure they pull vacuum? Usually there is a BB in that passage if I remember right. Or it's blocked by the gasket?

Let me consult my ancient text....

No bb’s and they open straight into the venturi bore

Sent from my iPhone using Tapatalk

 

[redone76]

That was an old dealer trick to improve hot starting. It won't hurt to plug them and get it running smoother if you don't have the hot starting problem (which you might with ethanol).

Okay that makes sense. How would you plug them? Drill and tap for a plug or JB Weld?


Sent from my iPhone using Tapatalk

 

[rvrrun]

Okay that makes sense. How would you plug them? Drill and tap for a plug or JB Weld?


Sent from my iPhone using Tapatalk

Either you are comfortable with. Tapping for a couple button head allens would look good and be easy to remove if you have the hot start problem.

 

[redone76]

Either you are comfortable with. Tapping for a couple button head allens would look good and be easy to remove if you have the hot start problem.

Exactly what I was thinking.


Sent from my iPhone using Tapatalk

 

[HALLETT BOY]

Just screw in a small sheet metal screw with a little silicone

 

[redone76]

Just screw in a small sheet metal screw with a little silicone

That’s the plan. See what I can dig up in my drawer of random bolts and screws. I was curious what the holes were intended for. As usual RDP didn’t let me down!


Sent from my iPhone using Tapatalk

 

[lbhsbz]

Just screw in a small sheet metal screw with a little silicone

no silicone....or RTV...which is what you really meant. Gasoline dissolves RTV sealant.

Go get some JB weld putty...the round log where you slice a piece off and knead it up...pack it in the holes, clean the excess off the inside and leave some extra material on the outside to keep the motor from ingesting it.

 

[ibelio]

you sure its a 401 most were 305? 401 in really big trucks

 

[redone76]

you sure its a 401 most were 305? 401 in really big trucks

I think you’re right. After doing all the research on the carb today I kept coming back to the 305. Makes sense as it’s all stock. My buddy just relayed what the previous owner told him.


Sent from my iPhone using Tapatalk

 

[redone76]

you sure its a 401 most were 305? 401 in really big trucks

Could be a 351 too??? I need to find the engine numbers and figure it out


Sent from my iPhone using Tapatalk

 

[ibelio]

should be stamped right side front of cyl hear [like chevy] ps have a real 401 core if needed

 

[redone76]

should be stamped right side front of cyl hear [like chevy] ps have a real 401 core if needed

Cool I’ll take a look! Thanks and I’ll ask him if he wants a 401!


Sent from my iPhone using Tapatalk

 

[redone76]

Ports tapped and blocked. Thanks guys!!!


Sent from my iPhone using Tapatalk