Dirty carb

I’m having trouble with the two barrel Holley that my son installed in the 232. Over the past six years it’s been rebuilt three times. The shop who did the last repair said debris in the fuel is the culprit. I run an inline filter with rubber fuel line. The truck ran great for about five hours after the last rebuild. The shop will clean it out again. The owner claims that no amount of filtering will remove the tiny particles. The tank was clean seven years ago when I installed it. I intend to replace the rubber fuel lines and install two in line filters. As an added measure I am going to temporarily run a boat gas tank to see if that helps. Thoughts?

Yes the truck has run very well. My assumption is that the Holley is quite old. The carb begins not to hold and idle and occasionally floods. I’ve been generally getting about a year out of a rebuild   I’m basing the crud theory on what the rebuild shop said. His premise is that if the truck ran well for a few days then ran poorly, crud built up in the carb again. He advised me to disconnect the fuel line at the carb and look at a sample in a glass jar. I haven’t got around to doing that. I’m not sure that I entirely buy the crud theory. This carb has been rebuilt at least four times. 

Edited by 69gladiator - Nov/23/2020 at 9:34pm

Yeah, "rebuilt four times" is immediately suspicious. Once is obviously ideal, allowing for misteaks, a second time fixes it. A third time I am immediately suspicious without a deeply satisfying amusing tale. Four times is ... 

how old is the fuel line? may be rusted inside it.