My 401 has sputters when I load it on a trailer or park it up hill since I had the engine rebuilt. Does anyone make a higher flowing mechanical pump?
If the motor runs good at full throttle under load then it sounds like your need to correct the issue is a simple Carb float level adjustment!
I agree with Steven. The pump doesn't know whether it's going up hill or not; a fuel pump problem would likely show up at high load/rpm. I'm thinking float level too.
Also if you are running a old stock points Distributor I have seen cases where the wire off the points that goes under the breaker plate and out the body had nearly all of its insulation dry rotted off it to the point that when the car hit a bump or dip in the road the wire would short out for a second and naturally the motor would cut out briefly! It got to the point where even the movement of the advance plate by the vacuum advance can would move the wire enough to short out the points!
