When Chrysler bought Rootes Group for its small car line in the '60's, they found themselves selling a foreign car w/a Ford V-8 in it! (the Tiger). A cheap alternative to a Cobra, the Cobra initially had a 260 cu inch V-8, before the 289 and the 427's. Those cars are much sought-after by collectors as they are the first Cobras! A friend of mine in Dania Beach FL bought one in the late 1970's for $26,000, which could buy you a decent home here at the time, everybody thought he was insane for spending that. Three years later he sold it for $106,000.
I'm not sure but I am guessing that both Buick and Olds used the GM aluminum V-8 which was later sold lock, stock, and barrel to British Leyland, who used it in the Rover 2000TC (where it became the 3500TC) and the MGB-GT, where it became the MGB-GT V8, I think it was called. It had the same performance as a Jaguar XK-E but for $1000's less, which is probably why they didn't last but 2 years. Buick also cut two cylinders off the end to make an aluminum V-6 which they turbocharged. It had a propensity for warping the heads and block if it overheated, which pretty-much ruined the engine, as it was not a good candidate from recovery from that, even w/a good machine shop decking the block and surfacing the heads.
Interestingly, Repco in Australia used the same aluminum engine block for their entry in Formula 1 and Jack Brabham had much success with it. I saw Jack Brabham race that series engine back in the Formula 1 races in the mid-1960's at Watkins Glen NY.
I think Olds even had an experimental plane they powered w/a V-8, to demonstrate its utility and ruggedness, though it may have been their 330 cu inch V-8 they used. That one was cast iron for the block, the 330 cu inch. That's back when each GM branch had their own engines.
Sean, I bet your dad had a lot of fun w/that car. Did you ever get a chance at the wheel?