The engine on the TR6 was unusually noisy, especially on acceleration, with sort of a slapping popping noise in time with the speed. I eventually figured out it was a bad exhaust manifold gasket, and now i can pick out that sound from a mile away - it seems to be especially common on Ford trucks and SUVs.
I've done a fair amount of other cleaning work around the engine, but had never really dismantled the top end past the carbs, when we rebuilt them. Everything was pretty crusty under there.