Pull the crank pulley around to TDC. Find the number one plug wire on the cap
and mark it corresponding position on the distributor with a marker of some
sort. Allow enough room so that the distributor can be rotated around to get
proper timing drop the distriutor so that the ign rotor and the mark you made
are aligned. If it doesn't, pull it out and restab it. Install the cap and
crank it over. If the timing is 180 degrees out it should continuosly backfire
through the intake. If this is the case, pull the crank pully back around to
TDC, pull the distributor back out then turn the crank pully one complete turn.
Restab the distriutor again. Leave the distributor clamp loose so you can
play with the timing to get it started. Even timing off 10 degrees or so won't
prevent it from starting. The get your timing light out and finish the job.
You can pull the valve cover to be certain of TDC to begin with but you'll
spend more time doing this then you would restabing a 180 out distributor.
Another way is to simply remove number 1 plug and put your finger in the hole.
When you turn the crank pulley over to TDC you should feel pressure building.
This would indicate the cylinder is on its compression stroke. Either method
is a lot simplier than removing a valve cover not to mention running back to
the parts house for more parts and more money.

Dennis
ASE Certified Master Auto Technician and Marine Engineer in training

I screw up... didn't read the manual carefully. How can I find out
the original position? or how can I properly re-install the
distributor? I have a 1978 mercruiser 260 (chevy 350 engine).