Cam and carb selections

These days a dual exhaust is a no Brainer. Cheap, available and sound good, why wouldn't you.
IDK? That’s what I suggested.
The car is a 75 dart swinger. Being built as a budget build to make frequent runs from Denver to Albuquerque, so torque for mountain passes is important. These high altitude passes are brutal
Is the engine old? Stock from the factory?