Thanks for all the responses and opinions.
The possibility of body/paint damage and scratches is one of the main reasons I am thinking of pulling the fenders.
The engine has to come out, the engine compartment has to be disassembled, stripped of it's current paint, painted, then the engine has to go back in.
It is a fresh, and modified 440 Sixpack engine so I will doing a cam break in and probably a fair amount of adjusting and tuning of the Sixpack carbs.
Lots of leaning over the fenders to sand, paint, and wrench will be going on if they stay on the car.
The fenders are currently very well aligned on the car.
Isn't there a way to mark the fenders' current location, (like drilling some very small locating holes) so that putting the fenders back on will be much easier?