Remember that the 425/472/500 Cadillac engines were designed to move big cars with smooth power for 300,000+ miles. There are a lot of advantages to using them for truck engines as I've been finding out. Many Chevy/GMC truck owners in my home state of Idaho would put them in tow vehicles to good effect.
Yep, My dad was a buick man. He had a 68 electra with a 430 that went about 250k miles that we drove to the wrecking yard.A 70 electra with a 455 that went about 250k miles and was still running ok and a 73 centurian with a 455 that had 290k miles on it when he sold it and was running fine. I had a 68 skylark that i put a 455 stage 1 engine in place of the 350. All of this talk makes me want to put a Buick 455 into something.