[Lynn]

Dave:

Don't blame you for not wanting to learn on a 69 Corvette. I love 69 Corvettes, and as stated in one of my first posts on this subject, believe they are grossly undervalued, especially with the L46 engine.

I definitely would not assume the guy checked the distributor curve. Most of the time, tune up would just set the initial timing to factory specs, change plugs, filters as needed, and adjust the idle and idle mixture on the carb. Hardly performance work. Still, that is the standard tuneup and what most folks want and get.

As for the GC code, you may have stumbled across the root of you problem. I am confused by the engine code. I can't find a reference for a GC coded engine for 69 Corvettes. There were only three L46 possibilites in 69: GD manual trans with K66, HW manual trans, and HX manual trans with A/C (separate code because it required a different exhaust manifold to bolt the compressor bracket). In fact, the <span style="font-weight: bold">only</span> GC code engines I could find were a 195 horse 283 police package engine from 1967 and earlier. Double check that code. If it is a 67 or earlier 283 block, then it doesn't likely even have a 350 crank, as the 67 283 would be small journal, and the 350 crank came only in large journal. Won't fit. Hopefully, I am wrong in this, but something isn't right. Have you looked at the casting date? Probably way hard to see on your Corvette. You may need a flashlight and small mirror. Casting date is located behind the passenger side head right by the bell housing.

Send me a PM if you wish to discuss this privately.