When you buy parts for the TTA.. you first buy them for a GN. The books are all screwed up as to crosses with these cars.
The computer, short block, esc, coil pack, ignition module, etc.. are all the same as the 87 GN. The only part that basically is different is the spark plugs, valvecover gaskets, and header gaskets(if used).. the rest of the engine.. 87 Buick.
Looking for 89 Firebird parts that fit your TTA will get you into trouble.
Jan.. I replace mine everytime I install a "freshened" engine.. As I take it off to get the block cleaned/machined/etc.. my last one I forgot to remove and loading it into the truck.. damaged it. As far as going bad.. it shouldnt, unless one phsically damages it.