Indeed they did. For the UK, I seem to recall tales of the time of one guy who pu a V8 from the Daimler 250 into an A - can't see that the effort of that was worth it compared to the Buick tiny block, but they were probably more available at that time in UK. And of course Mr Costello came up with the idea of stuffing them into Bs and, once BL realised that it was a good thing, nicked his idea and stopped supplying him with engines...
If the engine ever went bang in the A, the one that always appealed to me was putting in a period Alfa 2 litre twin cam - now that would be fun and would sound gorgeous, and would get a 5-speed gearbox with it.....still, since I' did my conversion to fit a B gearbox with overdrive that takes care of the latter, and the original 1622 sounds good compared to the wheezy 1798. Now, if I can just get that crossflow head for it...
MG Mark