LOL about old cars in Cuba.
I had heard that some classic car fans were planning trips to Cuba. But as you say, those old Cuban cars are not exactly in mint condition. Classic car buffs are much better off to visit car shows in America where the owners have restored and take good care of the cars.
The American classics that are used as cabs to haul gringo tourists about the Havana metro area mostly have four cylinder diesel engines made in China cleverly mounted to the original automatic transmissions. There’s adequate torque and horsepower to move the two ton plus behemoths in the 20-40 mph range with occasional bursts to 55 to 60. The wife and I hired a 1956 Pontiac Chieftan convertible with driver and guide/translator several years ago when our cruise ship stopped in Havana for a day. It was really quite a tranquil ride with the top down. The concept of an EPA never made it to the island and the air was redolent with the tang of various fuel chemicals. If there had been more two stroke motors, it would have taken me back to the times in South East Asia.
Good chance that 50’s Chevy has an eastern European tractor motor under the hood.
Many of them have Lada engines