Reply to "Should I build up the original engine in my GT5S or keep it stock"

Is the engine in your GT5S a Windsor? If so, there are a lot of good high performance parts available for the 9.5 deck 351 Windsor engine. New blocks are available in either cast iron or aluminum and the selection of heads and intake manifolds is quite large. Since you are a Ford dealer you most likely have had the chance to play with the new Shelby GT500 or perhaps even the new Ford GT. To even come close to the performance of those cars with a Pantera you are going to have to spend a huge amount of money and produce a lot of horsepower. If you just want more horsepower and still be able to enjoy the Pantera on the street, then getting into the 500 plus horsepower range isn't that hard to do.