I just replaced my LB9 with an L98 and had the distributor out. So I dropped the dist. back in lined up the rotor so it pointing to #1 cylinder and timing mark lined up at TDC. Got the car started up and was running fine. But when I put the timing light on it the mark was way off to the right around the 3 or 4 o'clock position. I did have the EST unplugged. I plugged it back in and it did the same thing. What could cause this? As far as I know everything is stock. Thanks

 

Rotor can point anywhere it points - BUT the #1 cylinder must be at TDC on the compression stroke. Then, wherever the rotor points, that HAS to be the corresponding plug wire for the #1 spark plug. If the rotor waqsn't pointing at #1 cylinder on TDC compression stroke before, doing that now doesn't do anything.

Remove #1 spark plug, place finger over hole, and have someone turn over engine manually until you feel the outward air pressure on your finger - then line up the balancer mark with zero - now the #1 piston is at TDC on the compression stroke. Then, remove dist cap, and wherever the rotor points, THAT corresponding plug wire MUST be the #1 spark plug - replace #1 spark plug, and rerun wires accordingly with firing order.

 

As far as lining up the rotor, thats what I meant. I had it pointing at #1 wire. And I did check the compression stroke to make sure it was at TDC. I just don't understand why the car is running fine but my timing light is showing the mark 40 degrees off.

 

The harmonic balancer has been known to slip on sbc.
Make sure the #1 piston is all the way up, use a coat hanger to feel the piston. The mark should be very close to zero.