Engine cutting out!

I have a 75 with a 355ci totally rebuilt and am having one major problem! From 0-80 all is fine, great accelleration, but right at 80mph it starts cutting out!This is the only time this occurrs! My mechanic that runs a custom speed shop thinks that the fuel pump can't keep the bowls full under this situation. He has tried all the adjustment he says are possible and still can not correct the problem. He suggests a new mechanical fuel pump! Has anyone else had this problem, how did you fix it? Does this sound like the correct fix? Any help would be appreciated!! Thanks!!
Gerry

I had this problem once before. It turned out to be the float adjustment. They were set to low.
Is your fuel pump stock? Has the fuel filter been changed lately?
Let us know how things turn out.
Sarge

My mech (Tim) said that he had gone thru all adjts possible including the floats, and the fuel filter is new! I think I will try the fuel pump! I want to change it myself, one to save$$, and to learn about these kinda things! Is it difficult to change? What tools do I need and are there any tips or tricks that I should know? Thanks Again!!!
Gerry

I haven't needed to change the fuel pump on "The Toy" (yet), but have on other cars over the years. Basic tools should be all you need (along with an hour or so of time and a couple of beers!).

If a new fuel pump doesn't cure the problem, then check your fuel lines from the pump all the way back to the tank. I.E. kinked, crushed, dented, etc. And if that fails, then you will need to check the strainer on the end of the pickup tube in the fuel tank.

This similar problem happened on my Dad's '87 Cutlass (RWD)V8. It took a few days to figure out. So as a last resort, I dropped the tank and cleaned the strainer out with solvent real good and blew it from the inside out w/30psi.air. After that, the car is still running strong for the past 2 yrs. There was a lot of "varnish" and gunk on the strainer, which was causing it to collapse itself shut at speed.
Good Luck!
Sarge