I tried to find the last post on this topic but couldn't. In a nutshel my 74 was cutting out at around 2800 rpm, backfiring, and then running smooth again. I was OK with fuel so I went after the ignition. Since my Pertronix was a few years old I figured a replacement was in order. I replaced it with a Crane XR1 which was a lot simpler to install than the pertronix and seems to work as well. I then changed all the plugs and found that my number 6 was fouled, so that cured a cold idle problem. I also changed the distributor cap for good measure although the old one was probably OK. While setting this all up my mechanical timing when set at 10 degrees initial was going to 38 degrees at 2800 rpm. This was because there was no bushing on the limiter. So I installed a bushing on the limiter and my specs now are 16 degrees initial going to 34 degrees at 2800 rpm. I have a lars recommended vacuum canister which kicks in another 10 or 12 degrees. During a test run everything felt good and the engine was livelier. There was no pinging even when the engine was lugged down to 1000 rpm in 4th and then accelerated. Part throttle acceleration also didn't cause any pinging. Wide open throttle was just the cat's azz. So here's the question. I've never run that much initial advance and while I'm not complaining about the performance I wonder whether others run that much initial and what effects it has on the engine. I'm also wondering whether I should bring it up a little so that I get 18 initial and 36 full advanced. Any thoughts would be appreciated.

 

give it a try

 

I suppose you could run the initial timing up as high as your starter will allow.

 

Keep advancing the timing 2 degrees at a time and then go drive to see if it spark knocks. At 16 degrees you are most likely as far as you can go but try it anyway. It will only give you more power. The higher octane gas you use the more timing you can throw at it. Just make sure to unplug the vacume advance and block the module and the tube when you set the timing. More timing equals more power. Right up until spark knock of course. Good luck!

 

So far starting the car hasn't been a problem. In fact it starts faster than my two new cars which isn't bad for an old carbed chebby. I'm also running 93 octane which is available in NJ so that may be helping in preventing any pinging or knock.