I would imagine there are differing opinions on this. My history is I have a 97 LT1 box stock. At 122k miles the factory opti fell apart. I replaced it with the MSD unit. I loved it and the car seemed to run better than it did new(smoother, maybe a tiny bit more power after fine tuning the timing). The car was wrecked at 147k miles. I now have a 96 SS/LT4 auto and the optispark has failed. My first thought was getting the MSD 83811 but I'm reading some negative info about failures out of the box and also pre-mature failures. From what I have seen, I would have to say that the MSD I put in my 97 was much better built than the stock unit. But I only got to run it 25k miles. Not a real long term test. So what gives? What is the best opti out there, in terms of long term reliability?

 

A "new" Delphi opti. rockauto.com is where I bought mine. AC Delcos are all reman now

 

I have never used a MSD unit so i cant comment on those. I have read about alot of MSD failures and have also read about a couple of AC Delco failures over the past 10 yrs. I can say I replaced my 93 optispark with 130K plus miles on and it was the original opti. It still worked fine but I was doing the water pump and figured I would do it also. I replaced the opti with a new AC Delco. I have had zero problems and its been over 2 years ago.

I would have to say AC delco ( Delphi) would be the way to go. Stay away from Ebay junk opti's that range from 70-140 bucks. Also i have heard of alot of failures with Chandler Motorsports opti's. They offer a lifetime replacement warranty .....I wonder why

 

I'm currently running an MSD opti and just a day ago i was driving through knee deep water (Arizona had floods all over) and my opti didn't cry foul once. There is a thread on LS1LT1 regarding the MSD opti so you may want to stay away from MSD. At least till they fix their issues. To be sure I'd go with OEM.

 

Still thinking on this. One big advantage is that the Delphi unit would save me about $200 over the MSD. Thanks for the input folks.

 

The one advantage of the MSD is that their warranty service is usually pretty good and when out of warranty, they will rebuild it for a reasonable charge. Just giving you some input you might not know.

 

A friend of mine is in the Corvette circle and he told me the MSD is the one to get. It's designed to be more waterproof than the stock unit. He put one on his wife's older Corvette and said it ran better than stock. She now has a 2013 so no issues at all.

I know in the past you can hit or miss with MSD products. Generally they're good but not always.

 

I've helped people on numerous sites with Opti problems, reviewing data logs to find problems with surging, etc. The MSD has proven to be the source of at least twice as many problems as the AC Delco/Delphi. Given the fact there are less MSD's in use, that's a telling statistic.

Last month, on LTxTech.com I helped a guy who had just had his MSD Opti rebuilt be MSD, and was having massive surge problems. We tracked it to the MSD - he tore it out, installed an AC Delco, and the problem was gone. At the same time I worked with two people on this site with similar problems - one had an MSD and the other an AC Delco.

My AC Delco (vented conversion) has been reliable for 14 years, but I only use the optical cam position sensor portion.