Need mechanic recommendation

[Dave Rifkin]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: [email protected]</div><div class="ubbcode-body">yep, 350/350 is a real good motor and the Q-jet is fine. Check your carb for the secondaries opening correctly and also the distributor. Correct Lynn, an underated corvette and motor. What gear is in the rear Dave?
</div></div>

The car has a 3.70 rear gear. The car is equipped as if the original owner wanted an LT-1 but didn't want to wait or pay the price. The car has the 4 speed, TI ignition, no AC and a 3.70 posi rear. Aside from the solid cam, Holley carb and aluminum intake, this car has almost everything that a '70 LT-1 would have. (minus the hood)

[njsteve]

Has anyone ever set up the advance curve in the distributor for the car? You won't believe the performance difference when the mechanical/vacuum advance is not set properly.

[Lynn]

Dave:

Dave: The LT1 wasn't available in 69 model year, and I don't know that the average Joe knew it was coming.
So your engine is an GD code, correct? I just tore down an HW code 69 350 that is identical except for the TI. I am thinking a good curve on the distributor and making sure the secondaries are working properly, and that thing will come to life assuming the internals are in good condition.
If you ever decide to get into the motor, a 178 cam, any of the period correct high rises, and a 4053 carb and you have an LT1 spec motor. You don't have to worry about being 100% numbers correct, so that would make it easier (and cheaper). Just save all your old parts.
Steve: that is the ONLY way we used to curve distributors when I was a kid. Who had a distributor machine? Pay someone to do it? Yeah, right. Get the spring kit, make sure you are all in by 3000 at the latest, set total advance at 38 degrees with the vac plugged off, and let the initial fall where it may. Many a SBC woke up with nothing more than that.

[Dave Rifkin]

Lynn, the engine in my car is actually a GC code. As far as the distributor is concerned; I have had the car to Corvette Paramedics and, when I took it there, I told them that I felt it was slower than it should be and asked that they give it a tune up and thorough once over. With that direction I would assume that they'd have checked the timing / advance but, we all know what happens when you assume.

So far I have received a recommendation from Steve and MosportGreen; thank you guys. I was hoping to find someone closer to home (Atlantic City area) as getting the car there and finding a way home might present a challenge. That and the fact that I am hoping to be able to use this person for future work on the car. If I can't find anyone closer I will most likely go with Steve's suggestion since that shop is closer than the one MosportGreen has offered to put me in touch with.

Ultimately I should just learn how to do this stuff myself but, I am afraid of making matters worse.

[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.

[njsteve]

I sent both of my HEI distributors (from my 72 Formula and Gramma's Firebird) to Rocky Rotella out in Nebraska, who works on a lot of GM stuff. He found things that I never would have noticed just doing a driveway advance spring replacement, like the vaccuum advance unit that was working intermitently on one of them, ranging from a 2 degree to a 25 degree advance change (and it wasn't even leaking) and on the other, finding out that it was shimmed wrong from the factory. He set up the curves nicely and limited the vacuum advance to 10 degrees total over what the mechanical curve was. What a difference! Very reasonable price, too.

Between the carb restoration by Cliff's High Performance Quadrajets in Ohio and the distributor curving, the Formula REALLY woke up. To the point where it breaks the rear tires loose when the secondaries tip in, in first or second gear.

Gramma's car was only 160 horsepower to begin with but the carb resto/distributor curve really smoothed it out and gave it a couple more horsepower. There is only so much you can do with a 7 to 1 compression 1975 smog motor.

[Dave Rifkin]

Lynn,

I agree 100% that the C3 &quot;bumper&quot; Corvettes are extremely under valued and are the bargain of the collector car world. In fact, I actually was hoping to be able to purchase a 1970 Z28 to replace the one I had as a teenager but, due to the skyrocketing values at the time I had to &quot;settle&quot; for my Corvette.

Regarding the GC code, I had a hard time finding any reference to that code as well but, found it in my copy of Rick Bizzoco's 1969 Corvette Guidebook. In the book he lists 4 codes for the L46 engine;

HW = L46 with 4 speed
HX = L46 with 4 speed and AC
GC = L46 with K66 ignition
GD = L46 with K66 ignition and AC

[Keith Tedford]

Another thing you might want to check is the cam timing. Often overlooked, it may need to be advanced or retarded. You are also fighting 91 octane gas and less while these engines were meant to be running on 102 and higher. With our old L78 car we had the timing backed off quite a bit so that the engine wasn't rattling. That takes away some power too.

[Lynn]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Dave Rifkin</div><div class="ubbcode-body">Lynn,

I agree 100% that the C3 &quot;bumper&quot; Corvettes are extremely under valued and are the bargain of the collector car world. In fact, I actually was hoping to be able to purchase a 1970 Z28 to replace the one I had as a teenager but, due to the skyrocketing values at the time I had to &quot;settle&quot; for my Corvette.

Regarding the GC code, I had a hard time finding any reference to that code as well but, found it in my copy of Rick Bizzoco's 1969 Corvette Guidebook. In the book he lists 4 codes for the L46 engine;

HW = L46 with 4 speed
HX = L46 with 4 speed and AC
GC = L46 with K66 ignition
GD = L46 with K66 ignition and AC </div></div>

Well, that is a relief! I felt bad even bringing it up, but feel much better now. I was wondering why there wasn't a code for K66 with AC in my reference book.

Hope you find the right guy to get it dialed in just right.