"Question...is it possible to mount the flywheel out of its correct (timing) position?"

As posted above by Jerry:

On all my stovebolt engines (216, 235, 261), the flywheels went on the same way, only one way.

There are 3 unevenly spaced dowels: there is only one way for the three of them to enter the dowel holes.
Maybe you have a flywheel that is missing a dowel, or two (as Jerry noted)?

http://chevy.oldcarmanualproject.com/shop/1941/41csm155.htm
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0633.htm
http://chevy.oldcarmanualproject.com/shop/1954truck/54ctsm0633.html

No muss, no fuss, no fretting.

One way fits all - unless you are missing a dowell or two or three




Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.