Original engine failed (piston rings) at 140,000 miles.
Power window motor.
Radiator.
Heater/AC controls.
Buicks early V6's leave a lot to be desired. Even though it had a 4-bbl carburator, it was quite slow and sluggish. It finally clunked out 8 months after I bought it, probably being tired from being underpowered and having to lug around a nearly 2-ton car for 15 years. I replaced it with a 403 Olds V8, which came out of a wrecked '78 Tornado that sat in my grandpa's garage for 14 years. The engine had only 56,000 miles when I installed it, and with a few minor tweaks, I turned it into a 270 HP powerhouse. This motor has enough torque to pull a freight train!!
The car handles quite well, except in snow. Seems like there isn't enough weight or traction in the back.
The interior space seems small for a 18 foot long car. It's still much more comfortable than some new ones, and I can squeeze 6 medium to large adults in without too much of a fuss.
I love the styling, I wish we still made cars that look this good.
The stereo impressed me for such an old car. It blows away the one in my wife's '96 Accord.
I prefer the older full size GM cars myself. They handle and ride a lot better then any new compact ever will.
I have an 84 Buick LeSabre, 86 Regal, and just bought an 83 Oldsmobile Delta 88.
You made a good choice in putting a V8 in, most people put that little V6 back in.