Altered timing mystery

Had to take out my dizzy last week to loosen my PAS pump (to fit a new belt) and when I put the dizzy back the vehicle wouldn't start. Checked the dizzy again - nothing. Turned dizzy thru' 180 degrees and still nothing. Lined up the timing marked and found that the rotor arm was pointing at No4 cylinder instead of No 1!? Moved all of the HT leads and it started first time (better than ever) How did this happen? I thought a dizzy could only go in 2 ways (right or wrong) Or was it set up wrong in the first place. I live in the middle of nowhere so I can rule out practical jokers.

I presume you accounted for the fact that when the drive gear engages with the cam gear the rotor arm moves by 30 degrees and you also have to get the oil pump drive lined up as well. Although it does happen sometimes, it is rarely the case with V8's to be able to "just pop the dizzy out" and then "pop it back in".

Always mark everything up properly and take your time, make sure you know what the timing should be and in which order the leads should go, make sure you understand what each wire does and where it should go. If it doesn't run properly, make sure you know how to time the engine from scratch.

I've had dizzies out of my old 4 cylinders before and they just 'pop in and out'. I didn't realise it was that complicated. Still cant my head round how it can go back in a different place yet locate with the key in the base. Now I know that it does change I can sort the timing statically next time (if there is a next time!) and then dynamically later on.

Cheers for the info