My wife was at a medical appointment in Vancouver last week and spotted this sitting on the side of the road with a "for sale" sign on it.
It had been in storage for the last ten years and it's mine now. She bought it. (I guess that makes it hers)
I have had over 30 Corvettes and presently have a C6Z, a C5Z and a 78 S/A. My first Corvette was a 69 427 in 1970 so this is kind of special.
Enough of the bs.
When I got this home the timing at 800 rpm was set at 27 degrees advance.... It sounded like marbles in a tin can so the moron who did this probably hadn't seen the ball since the kickoff. The manual says 4 degrees but for the L88, 12 degrees. I set it at 14 and it runs really nice with no ping when you step on it. I am running straight gas (no ethanol) at 91 octane. It is an original engine that has never been out of the car and is a "points and condensor" distributor that has been converted to electronic.
Am I running too much timing? 14 initial and 36 total. 427/390.
Thanks
Grant
Below is a cellphone pic of the car as my wife found it last week before she bought it. It looks better now.

 

the 14/36 with vacuum disconnected sounds perfect. How much is the total with the vacuum connected, around 52?

 

It seems to like more timing but I didn't want to go overboard. Not sure what initial I can get away with but GM's 4 degrees is really stupid. I am thinking of bumping it up to about 16 but was wondering if that might be out of line. It's a 45 year old stock motor and I just want it to run smooth without any problem. We have straight gas here and I use 91 but can get 94. The thing was banging and hammering away in the marbles can on 94 octane and just got it so have lots to look at. Figured this one out pretty quick but wasn't sure what guys were running for timing on a stock motor.

 

Use a vacuum gauge when setting the timing and find the point where the most advance is achieved with the highest vacuum gauge reading and the needle on the gauge being steady. Then you can slightly retard it a little bit.

Use your light and see what the reading is. As I have mentioned in previous posts. I use a timing light as an information tool...and NOT the "be-all and end-all tool". WHY??? do you ask. As previously mentioned. I have encountered so many Corvettes that have the outer rings spun on the balancer that TRUSTING the notch on the balancer is a joke. I often times check the notch by using a stop tool in number one cylinder and manually turning the motor and making marks on the balancer and finding TRUE TDC.

Also...for what it is worth...I block off all vacuum for the headlights, wiper motor, HVAC and power brake booster. I make sure the engine is running smooth and then I connect the vacuum for the power brake booster and see if anything changes. Then I drive it and see how it drives.

But this is also assuming that I have checked the vacuum advance and see how ti performs and if it has been changed and might not be what I want in regards to how the engine is performing. I do what I mentioned above as a quick starting point.

Then I go deeper if the engine seems to not be acting how I want it. Checking the KV of the plug wires and plugs, spark plug gap and plug condition and what the plugs look like. Are the plug wires routed correctly or "zip-tied" together. Is the engine producing excessive crankcase pressure due to bad rings and the PCV valve can not keep up. Exhaust leaks, etc. And performing a compression test if the engine seems to having a hard time running right. Which will usually be perform pretty quick if some of the initial tests and checks show no improvement.

DUB