How do you check the timing on the lt1's? I have an adjustable MSD and have no idea how to do this. When i installed the unit the rotor was pointing to 12:00 and the new one was in the 1:00 position. Is this a problem and will my timing be off? The unit went on the gear smoothly so i know it was lined up right. Also what +/- timing should it be at with my mods?

 

There's no easy way to check it. You'd have to get a light and put some timing tape on the balancer, but even that's difficult since the hub isn't keyed.

You should NOT use the MSD opti to change ignition spark timing. It's only meant to be used when the cam timing is advanced or retarded with an adjustable timing chain.

 

It's actually pretty easy to check as long as the opti is installed correctly and you have a scan tool.

 

Except the MSD "fools" the pcm by moving the optical sensor which is what the pcm gets it's information from.

This is exactly why I felt it was less than good for MSD too offer this option. Only a TINY fraction of folks are capable of compentently using it the rest will just use it too cause themselves trouble. Already had to help one guy pull one off after he screwed with it because the car did not run right after install. He ended up damaging the mechanism, turned out 2 plug wires were switched and he should have left the opti alone. Yes it was his mistake but frankly I forsee this sort of thing happening MUCH more frequently than the feature being used properly.

Far as indexing it too the cam, it should only fit one way.

 

The scan tool will only tell you what timing the pcm is SENDING to the engine, but it's not always the timing that the engine is running at. For instance, if the opti is installed wrong or plug wires are crossed, then the scan tool won't pick up on that.