Cam installed 180 degrees out of alignment - how is this possible?

[markatspace]

I recently had a head gasket problem.
While removing the head I noticed the timing marks on the cam were not aligned.  The Cam was aligned 180 degrees from the factory alignment marks.
I fixed my head gasket reassembled the car as it was and it runs fine.
Can the Cam be installed 180 degrees out of position? Would you need to change the firing order on the distributor to make the car run? How would this be possible?
I would like to find out? any help?   thanks?

[stickandrudderman]

Are you sure you were checking for TDC on the firing stroke? If you rotate the crank one more turn then you'll find the cam in the correct position.
In any case the short answer is yes. It just means re-arranging the HT leads in the cap.