Holley carb question

[Donald H.]

This has probably been addressed, but I could not find an answer by searching.

I recently purchased a List 3367 which is date correct for my 66. I got it for a very good price, but it has a very nasty areas in the base. It has a lot of JB Weld that someone used to try and fill in what appears to be some pretty heavy pitting. By doing some other research, I found out this is a result of the heat transfer slot in the cast iron intake.

I have read either on this TDB or the Corvette forum about tapping and putting a plug in the slot to prevent this kind of damage. But I also understand that there is supposed to be a stainless steel shim under the carb that prevented this kind of damage.

If the shim protects the base, why not just put the shim back and not mess with plugging the slot? Or am I missing something?

By the way, to the uneducated like me, seeing this damage first hand make it very easy to recognize the damage in pictures of carbs on Ebay and elsewhere.

I've checked Colvin's Chevrolet by the Numbers and he shows the List 3367 being used only on the 66 SB Corvette. Is that correct?

Thanks,

Don

[Timothy B.]

Re: Holley carb question

Don, If you just install the stainless shield it may be fine but with today's ethonal gasoline it will percolate at a lower temperature that the old leaded fuel. That hot slot is best plugged and in the summer months it may or may not be necessary to wire the heat riser open. This will reduct the heat greatly under the carburetor but keep in mind with a cast iron intake manifold some heat is good.

Onn my 67, all that's necessary is to wire the heat riser open in the hot summer months and the hot slot stays plugged all the time.

[Jim T.]

Re: Holley carb question

I wire my heat risers open to save the muffler on the passenger side, my current right side muffler has been on the car for over 25 years due mainly to excellent muffler construction and wiring the heat riser open. Walker muffler.

[Joe L.]

Re: Holley carb question

This has probably been addressed, but I could not find an answer by searching.

I recently purchased a List 3367 which is date correct for my 66. I got it for a very good price, but it has a very nasty areas in the base. It has a lot of JB Weld that someone used to try and fill in what appears to be some pretty heavy pitting. By doing some other research, I found out this is a result of the heat transfer slot in the cast iron intake.

I have read either on this TDB or the Corvette forum about tapping and putting a plug in the slot to prevent this kind of damage. But I also understand that there is supposed to be a stainless steel shim under the carb that prevented this kind of damage.

If the shim protects the base, why not just put the shim back and not mess with plugging the slot? Or am I missing something?

By the way, to the uneducated like me, seeing this damage first hand make it very easy to recognize the damage in pictures of carbs on Ebay and elsewhere.

I've checked Colvin's Chevrolet by the Numbers and he shows the List 3367 being used only on the 66 SB Corvette. Is that correct?

Thanks,

Don

Don-----


The type of damage you describe is inevitable if the stainless steel heat shield is omitted which is exactly what someone must have done in the case of this carb.

Even if the heat shield is installed properly, the heat slot is the greatest killer of carburetors ever invented. It causes other problems besides the erosion of the throttle body and includes things like warping of the throttle body and warping of the float bowl. It also causes much more rapid deterioration of the carb gaskets and seals.

GM abandoned the use of the heat slot after the 1969 model year for ALL carlines.

[Donald H.]

Re: Holley carb question

Thanks all,

I learn something every time I post a question.

Don