Nice, another Optima rebuild. I did the same, got a used Turbo Optima, and fitted it with a repro first Optima shell. Not in boxart, but still trying to keep it oldskool looking. I haven't posted a rebuild thread here, but on a fellow forum you can find more info about mine:
http://www.rcgroups.com/forums/showthread.php?t=2106044
A weak spot of the Optima is the chain. It tends to keep stretching, especially if you fit stronger motors. It also lacks a real slipper clutch. Since you have the Turbo, you already have the golden shocks, which are better than the red ones, less prone to leaking and getting dirt inside.