How many cases are there of the same block being offered with completely different types of cylinder heads in the same car in the same model year? Examples that come to mind:
1) The Willys Aero with the flathead and the F-head sixes. I can’t speak to fitment of these engines in Jeeps, nor to the Willys flathead and F-head 134 CID fours.
2) The Peugeot 405S and 405DL were SOHC. The 405Mi16 was DOHC.
3) The Saturn S series: SL1/SW1/SC1 (SOHC), SL2/SW2/SC2 (DOHC).
I know Studebaker made their flathead 6 into an OHV in the late 50s or early 60s, but I don’t think they offered both versions in the same model year. But I’m no Studebaker expert.
What other examples are there?