1986 Dodge Truck Dies when coming off highway

When I come the highway, the runs roughly, then dies. It restarts immediately. 1500 miles ago, I had a new cam & lifters, fuel pump, cap, rotor & carburetor kit installed. The shop also tried to fix the power windows & in doing so pulled the window lift/hot run & start relay apart. The truck never acted like this until after the above work was done. I have since put a new rebuilt carb on it & a mechanic filed the points on the relay & the windows work now, but it still dies coming off the highway. City driving is not an issue.