This is a very interesting story. Engine was overhauled in Minnesota three years ago. It hasn't been right since. Chrysler Crown Marine Engine M7 M27 M47 265 cid flathead Chrysler 6. Engine kept shooting #1 spark plug out of the plug case on #1 xylinder three times over the last three years. The cylinder head around that #1 hole was 650700 F which is way too hot.