Ran across this thread searching for something else.

This is what I did. After looking everywhere it occurred to me these are the best pics I have of the coil mounting and probably don't have good shots of them in the car.





The brackets are 16ga steel and attach to the valve cover bolts with some stainless washers and 1/4" tall stand-offs. I'm fairly certain the air tube will get in the way with them in this location. There's also a bracket welded on the back that connects to the intake with the injector cover standoff stud. After getting the engine in I found the odd bank bracket needed to be moved forward about 3/4" to avoid hitting the wiper motor.

The injector covers did fit with this setup, but I've since installed shaft mount rockers that required a 3/8" spacer be bonded to the heads so the stock valve covers could be used. Instead of making new coil brackets I simply added a 3/8 spacer to the bolts that fasten the inner brackets to the intake.

I do get a tiny bit of oil seepage around the spacers, but it's easier to wipe it off every 3-4 months then to fabricate sealed top studs.

This setup is using my DIY Arduino based controller. Info can be had here [link].

 

Owned my impala for 4 years and I changed my opti 8 times.... So now I got a torqhead kit it's much more plug and play then lccc kit buy my suggestion would be invest in the torqhead kit...

 

I'd love to discuss this in detail just for my own curiosity. Were you opening up the failed optis to diagnose the failure? Two a year for four years tells me you were either buying junk optis or had some other underlying issue.

Optis have several layers of failure possibilities. In my opinion here are the three most common.

First and foremost is coolant contamination. An EWP conversion solves this.

Second is oil contamination. Anyone who replaces an opti without replacing the oil seals is asking for trouble in the same way my daughter's bone-headed boyfriend would change his oil without changing the filter. Why, why, why?

Third is the optical sensor which has layers in and of itself.

Having owned several brands of optis I can say with certainty these sensors are not all created equal. The Delphi base I bought from Rock Auto had a completely different sensor than the cheap remanned Delco it was replacing. The thickness and offset of the sensor was such that the Mitsubishi J520 sensor wouldn't fit without milling the base and adding spacers.

These sensors can also fail from excess heat. The phototransistors degrade with prolonged heat exposure and the switching speed of the transistors change over time, causing a loss of high res signal. There's a lot of signal conditioning going on inside these sensors as well, and all these contributors can add up.

I've also personally caused a broken solder joint by beating the hub out of my opti base without first removing the sensor. I then dismantled the sensor to see how it was built, and I can say with certainty the possibility exists for cold solder joints failing from thermal cycling.

Long story short, when compared to a hall effect sensor used in everything made since, the optical sensor is problematic. Because Mitsubishi stopped making the OEM sensor long ago, I highly suspect that the majority of remanufactured optis that are widely available contain the original aged sensor, or sub-standard chinese knock-offs. I've found the AIP Electronics reproduction part to be the most reliable piece hands down.

This is a very spendy option, and I'm curious if it's equally as plug and play on a Vette where the CCM is the ALDL bus master during normal operation.

Though a 411 conversion is certainly superior to the stock LT-1 PCMs, converting to OBD2 isn't a direction I'm willing to go with this car mainly because I enjoy using eehack far too much. But it's the only option that takes the J520 optical sensor out of the picture.

 

I’m on mobile so I can’t be sure but it sounds like you’re the same person from the other thread. In any case, before recommending this option you should probably check to see if it’s even an option in the first place. Right now it is not—and has not been for over a year now. Nor is it looking like it will be any time soon.

 

Just picked up a clean 92 vert that had sat in and nice garage covered for 5yrs. Had to shock the fuel pump with a 18v drill battery to get the fuel pump running again. Obviously had a slight misfire when running and so I quickly researched and found the LTCC. As being a former GM tech I was full aware of the opti and the problems surrounding it. And had I not found the LTCC I'm not so positive I would have bought the car. Anyway got it home ordered the LTCC and torn it down. Directions were a little less than desired and my printed version was missing the pages for the 92 corvettes and what to run the white wires to. It was this page that got me straighten out so thanks TorchTarga94! This is where I mounted the coils in the pic was the mock up stage so disregard. Now to clean up under the hood I wonder if the guy was afraid to wash under there with the opti lol.

the long bolts it has since be refined.

 

I get that some guys want to leave their car as stock as possible. But for the rest this is one of those mods that seems like a no brainer in today's day. You can get LS coil sets for next to nothing in a salvage yard. So for under $600 you never have to mess with an opti again.

Now I never owned anything with an LT engine. Mine's an 84 that I LS swapped. I love the coil on plug ignition for tuning and for nitrous. It's been 100% reliable.

But after reading all the opti horror stories on the forum over the years I don't think I would mess with it personally. If I couldn't LS swap it I would absolutely put LS coils on it.

 

I see i had a strong opinion in 2015 on this

i want to note that i am now converting to LTCC , because I am worried about the spark blowing out at high rpm’s with the boost (and nitrous) i plan on running in my 383 splayed main i am having finished up. Those are concerns i have even with an msd-6

so i have bought a used ltcc at half price and will be using it, alongside the stock 1993 ecm - modified for boost

 

I did this on my 93, when I had it. I loved the ltcc. That said, you still need a properly functioning opti to use ltcc. On my 96, I would prefer to do torqhead.

 

I'm glad you found this thread helpful!! My Petris opti and LTCC kit is still going strong 🤙😎