The 'performance potential' is very minimal as it was not designed with 'performance' in mind. Besides there is almost ZERO hi po parts available. Your basic camgrind can be had from any grinder, heads can be opened up and 'blue printing' the rotating mass and block is about all you can do. I don't even recall seeing any sort of aftermarket intake manifolds offered for it ! It would all certainly go under the 'period correct' heading as it is all basic hotrodding engine preparation. Try to find a builder that is either still running or has NOT been exposed to the elements( can still rotate) as the pistons could be frozen in the cylinders.