Technical 292 runs good/runs terrible

I'd bypass the pump with an electric one temporarily if I suspected a bad pump.

 

My old 57 312 ran great in cool weather with a 600 Holley . It got hot and it ran like shit. Built a wooden carb spacer from marine plywood, wrapped the fuel line from the pump to the carb. . Cured my problem. The fuel was boiling in the carb. Got stuck in a fast food drive through pulling my pop up camper. That was embarrassing.

 

trying to find a cheap one now to confirm. thanks for the sanity check

 

New fuel pump? but did you suck debris from the tank into the new pump and possibly damage it. I always install a filter someplace between the tank and fuel pump. Those clear filters under pressure between the fuel pump and carb are a fire waiting to happen. Also that crossover exhaust at the front of the engine adds a lot of underhood heat. might be vapor lock?

 

So it did the same thing with the carter as with the holley? So you can rule out carb it sounds like. Already been mentioned, the fuel pump, filters, etc. Does kinda sound like something is getting hot maybe. Is there an ignition wire or something that could get hot and shut it down until it cools?

 

There is a good chance the tank pickup filter sock ( if it has one) or the open end of the pickup is plugging up with debris on the longer rides. Once you slow down or stop the back flow of gas from the top of the tank clears the trash and the engine runs like new again till the next time. This is a very common problem on tri 5 chevys. Check it out!! Ralphie

 

well, I finally figured it out!!! It was that damn glass fuel filter between the pump and the carb. the black ring is a square cut oring isolator that I guess keeps the filter element in place. fuel comes in through the hole (at right) then through filter-outside to in, then through the holes in the tube again and out to the carb.
that oring had come out from between the knurled nut and the filter element, and was around the element and sealing up against the inside of the glass. I could just barely blow air through it. Replaced that piece of crap with a $3 metal Delco filter from Autozone. Runs like a bat out of hell now...up, down through the gears, full throttle, all around town! Best part is actually making it home on it's own power. Thank you all for the suggestions and ideas on stuff to look for. Needless to say, will never use one of these again.

 

your post got me on the right track, Thanks!

 

Great! This story is a lesson on perseverance.
Good outcome

 

Glad to see you found it. Good job !! Sometime's the simple problems are the hardest to solve.