Rochester Carb Challenge

[OregonC20]

I purchased a freshly rebuilt Q jet Rochester 4 barrel carburetor from Carb Junky's a few months ago and I had a local shop installed and tuned the carb in my truck. I have a 1970 chevy big block. I took the truck back twice to the same shop because the truck would die on me while driving after 10-15 minutes of driving it , no issues during the first minutes of driving when I started the truck after sitting overnight. I would press the gas pedal and the truck would stall out. The shop then started blaming Carb Junky's for not rebuilding it right. Anyways, I took my truck to a more reputable shop and had the carb rebuilt again, only to take back again because the truck was hesitating when I soft press the gas pedal. Now I am being told that "the accelerator pump is malfunctioning or/and keeps breaking". I was also told the the gas in the truck "has a funny odor" and I was asked if I had put a gas additive in the gas tank, which I did not. Hopefully they will figure this one out soon. Thank you for reading.