If original, get those tires off there NOW. Just a blowout waiting to happen. They're Goodyear Eagles, and they're surely dry rotted by now. Check for tread cracking. And with 33K on them, they're at end of life. If they still have tread on them, they've been replaced and are not original. Eagles didn't last but around 35-36K max back in those days if you were easy on them.
I bought a 1987 Olds 442 with 19K miles on it (22K miles now) and it was original darn near everything. The friggin' tires were NOT in the greatest of shape, and the headliner foam underneath that perfect headliner fabric was crispy and crumbly. So the headliner will need to be replaced. Luckily, the ROWL Goodyear Eagle GTs are reproe'd now in 215/65/15, so it's getting new shoes that look period correct, eventually.
GLWS. They're nice cars. But they're still Buicks and they're still V6s...
