The opti-spark I have on my LT1 is misfiring badly so it looks like a swap is upcoming. I've been told by some 4th gen guys that MSD opti's are junk (apparently they are sometimes faulty out of the box even) and not to waste the money on them. Anyone have any experience with them? What about the Accel units? I dont want to waste my money on a piece of junk.

 

I am a firm believer in the AC Delco units. Check the wiring going to the opti also. It tends to corrode and cause problems. Check all of the plug wires as well. They can also corrode.

 

Nothing wrong with the second version of the MSD units. The first version had some problems with the way the rotor mounted causing them to fly apart (just like the regular optis can) because they weren't being put together correctly by the end user. Also the way they went into the cam was different as well, but they redesigned it to mount just like the stock units and alot are running them with no problems at all.