About 20 years ago i bought a 68 GS 400 - 4 speed car from a nice elderly lady that clams to have owned it since around 1972, and had made no changes. It actually had less than 50,000 miles on the odometer. I pulled out the engine, trans. and 3:42 posi rear to put in a go fast 455. I raced it for a lot of years but finally the block broke and now i am putting it back to original, but upon cleaning the grease off of the "original " engine, i find that its a 430. Has anyone ever heard of a Buick dealer putting bigger engines in A body cars like Royal did for Pontiac, and Yenco for Chevy?