[quicksilver97ta]

It's been awhile since I visited this issue but I know there are many complaints about aftermarket opti's. Best bet is a genuine GM unit. There's some contact info at Camaroz28.com on a Jason Cromer at a dealership in FL I believe, anyway he beats everyones price on GM units. It's routine. There is another contact, 'Dal' I believe but I got mine from Jason. Just go there and do a search.
Stock opti's are the best or at least get the least amount of complaints. The only catch is the rotors do not hold together well above the stock rpm limit of about 5500. I wasted 2 this way. They have tiny screws that hold the rotor which back out, also the plastic welds that hold the metal tab on the rotor give up as well. You can disassemble it and locktite the screws and add a pop rivets to the rotor for a more reliable set up.
The last thing I did, knock on wood, was buy a new opti and then buy the MSD cap and rotor kit. It's the best set up all around, still did the locktite though. It also adds an extra screw to hold the cap tight as they die with moisture. If you have a non-vented opti this would be a good time to convert, the vented opti really improve the moisture problem. And a big 'good luck' as working on the opti just bites. And remember, you can just pull the balancer and not the hub, you just have to clock it right to clear. And there is no getting out of pulling the water pump. Good distributor, bad location.