Thank you LanX! You're correct in assuming this will be used in a loop. An FCGI Loop infact.
Some older scripts were not designed with lexicallity in mind and simply make use of global variables if and when they're values are needed.
Localizing these at the beginning of the FCGI Loop allowed me to run the given program under FCGI without re-writing it. Early indications show an improvement of over 500%.
Although it is not a perfect solution - it seems to be working.