Holley four barrel carb exchanged for same list # NO!

It depends do you have an inline filter as well?
My 454 has a filter in tank as well as an inline filter and a filter at the carb.
I would expect zero debris.
If you just have a sock filter in the tank it may have a large mesh allowing smaller particles through. Is this a fact No! just a thought

As mentioned, there is probably an inline filter somewhere you should check. It is also possible for dirt to enter around the air cleaner is improperly installed or a dirty or cheap air filter. This can cause a problem within the carburetor.

Damage to the carburetor meaning what? If you get dirt in the carb it won't work properly. If you let gas sit in it over a long period of time it will gunk up the jets and not run properly. If you sucked up dirty fuel you didn't ruin it but it needs

to be removed and cleaned out. You need in line filters, clear ones so you can see what's up.

Does the gas smell funny? Gas goes bad, sooner than you think. Always use sta-bil in engines that sit.

I cannot imagine the carburetor would ever be damaged if no fuel was getting to it.
What fuel pressure did you measure?

Since you indicated you don't know much about carburetors, something that may interest you is filters will normally take out dirt that gets pumped up from the gas tank, as others have mentioned. However that is not normally the cause of a problem. The normal cause is old gas that has turned to varnish by being allowed to sit for some time. The volatile part of the gas evaporates leaving the varnish behind, and that gums up the little holes, called "jets", that allow gas to flow to the engine.

Another cause is water left over from the alcohol that is now added to gasoline to meet emission standards. Stuff grows in the water and that can block the jets. Also, water won't go thru the jets unless it is mixed with alcohol.

So, change the filter. It probably looks like a very short cigar and is right at where the fuel line connects to the carburetor. (It may be on the top right on the Holly if I remember correctly.)

I don't think your Holly has a drain plug at the bottom unless it is very old, but if it does, you could drain out the debris and water. Taking the top off of the carburetor is a job better left to someone familiar with rebuilding a carburetor, so removing and exchanging it with a rebuilt would be the better choice. Good luck.

Your topic title and questions all confuse me. Have you swapped the OEM carburetor for another? If you have, I think it wouldn't've been easy to get an exact match.

Far as the tank is concerned, didn't you pretty well clean/purge this one out with all the fuel pump changes? I thought you'd said it was clean.

LONG time ago, but my recall is all the filtration ours had was the sock in the tank and an inlet filter in the carb. I added a plastic inline filter in the line at a joint along the frame rail near the driver seat.

I have seen guys blow air through the line into the tank and blowing the sock off it was so packed with junk.

Carb adjust 2nd line with filter turned clear NO!

Sorry, can't make heads or tails out of your title.

thank you all for your input. I found the problem.

It's always nice to wrap up a query by letting us know what the cure was! It's kind of the price for all the free advice.