I don't know what exactly Jegs sell, but consensus on the board says true OEM from GM. thepartsladi on e-bay sells the real deal for a good price. But there are other sources. A quick search on this site should reveal alternate sources.

 

I got mine from summit, GMPP brand (GM I am assuming) its about $100 cheaper then a dealer. So that is another place you can look into.

 

Just for your edification, I say this because of experience. I myself have had a similar issue and it turned out to be the opti. I am not one just to throw out opinion just because I have heard it on another post. I changed plugs, wires, ignition module, coil, and bypassed the MSD box. Once I swapped the opti all was good.

What I am getting worried about as our cars get on in years the quality of the "new" parts that are coming out is going to decline. For example, this weekend I was working on my Chevelle due to a starter problem. I ordered a BRAND NEW starter from Delco/Remy just to be sure that there were no issues with reman starters. 3 BRAND NEW starters later, it works. And don't get me started on voltage regulators. Point being, we may start seeing this kind of crap with new parts now that our cars are pushing 15+ years old. Hell, in 4 more years, I can title my Camaro in VA as an antique!