As far as the waterpump/OptiSpark, I don't find it necessary to change the pump and Opti as a maint. item, but I do highly recommend that you keep a close eye on it. The problem is the Opti does NOT like water/moisture, and since the intellectual engineers at GM placed it directly beneath the waterpump, it sort of sets it up for failure. Many times the waterpump will lose it's bearings and leak onto the Opti. This can be a bit unpredictable as far as when it will happen (my pump went at 25,000 miles and took the Opti with it). Some LT-1 cars still have their original pump/Opti, and some have had problems with less than 10,000 miles on the car. That is why I say keep an eye on it.
Feel the front of the Opti. Does it feel wet? Take a long handled inspection mirror and get a look at the weep hole under the waterpump. A bad opti can leave you stranded, that would go for a bad water pump as well. The typical signs of a bad Opti include bucking, sputtering, having the car start and shake like a wet dog as it shuts off. Once moisture has entered the opti through the seals (which at this point are rather old, and don't seal well if it's the original unit) it corrodes the discs that are inside. If the discs cannot be read due to corrosion, the car runs very poorly if at all.
If you really like this car, and it has the original pump/opti setup, just plan to have it replaced in the near future. Typical shop cost for such a job is over $1,000.00 that is why people warn potential owners of the condition. And always change out both units, never just one. While you have the car apart, it's just a better idea.
Good luck with the potential purchase of this car. You'll like the hardtop. I have a factory hardtop as well, and it really stiffens up the car in the cowl area.
![Smile :) :)](https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png)
Let us know how you make out.