I was wondering if there is anything that is out there to get rid of the Opti-Spark Distributor in my 1994 Z/28 LT1 engine?


There are a couple of options for converting away from the Opti-Spark. One in particular is from EFI Connection but this requires a serious investment of multiple components to convert the existing LT1 engine over to essentially an electronic fuel injection style spark control like the system found on an LS1 engine.

This is a very nice conversion but the expense pushes it far beyond $1,000 depending upon where you get the parts. Buying all new parts will be quite expensive but the benefit is that this conversion would also make a few more horsepower. Much of that depends upon the modifications to your existing engine. If your LT1 is stock, any power improvement would likely not be worth the investment. 

You didn’t specifically mention a problem, but we will assume you have been having issues with your existing system. The early Opti-Spark systems used in the 1993-95 cars suffered from problems due to condensation forming inside the distributor housing. This caused spark scatter and drivability problems. This issue was minimized with ’96 and later engines with a distributor housing fitted with a simple 1/8 inch vacuum hose fitting that was connected to intake manifold vacuum.

This conversion lowered the pressure inside the distributor cap and pulled the condensation out of the housing. If you’re willing to do a backyard conversion, it would be worth the effort to convert your older distributor with a homemade vacuum port using vacuum tubing and some epoxy to seal it into the housing and then connect it with a small vacuum line to the intake manifold. Of course, you could also just convert to a complete new 1994 and later distributor.

It’s also been noted that the drive seal from the water pump could seep coolant into the distributor housing that would also cause similar ignition difficulties. While it seems odd, it could be that replacing the water pump with a higher quality pump like a Dayco pump could reduce ignition problems. The clue would be coolant residue inside the distributor housing.

One point that’s worth emphasizing can be found in the name of the ignition.

“Opti” refers to an optical trigger used instead of the more commonly found magnetic triggers used in most distributors. This optical trigger is far more accurate and when driven directly off the camshaft as is used in the LT1 offers a far more accurate spark trigger system than the more common cam-driven distributor gear that can suffer from backlash and cam twist issues when employed in higher revving engines.

Based on this, it would seem worthwhile to improve the durability of your existing Opti-Spark system rather than just replacing it.

gm opti spark ignition module
The Opti-Spark system first appeared in 1994 Corvette and Camaro LT1 EFI engines. The front-mounted distributor was driven off the timing chain using an optical trigger instead of the more common magnetic trigger used like on the GM HEI distributor. (Image/Summit Racing – Procomp Electronics)
Share this Article
Author: Jeff Smith

Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. Smith began writing for Car Craft magazine in 1979 and became editor in 1984. In 1987, he assumed the role of editor for Hot Rod magazine before returning to his first love of writing technical stories. Since 2003, Jeff has held various positions at Car Craft (including editor), has written books on small block Chevy performance, and even cultivated an impressive collection of 1965 and 1966 Chevelles. Now he serves as a regular contributor to OnAllCylinders.