I have a 307 with msd 6al w/ distributer coil and wires. champion copper plugs gapped at .35 midlength hedmen headers, edelbrock performer rpm and edelbrock 600cfm carburator. What should I time it for. Looking for drivability.

thanks,
Jon

also where are the block numbers stamped?

 

bump

anyone?

 

I've ran most of my small blocks (including my current 11:1 355) @ 38 degrees on pump gas. I'd say start at 34, on see how it goes from there. If your not looking to tune it for things such as weather, fuel type, etc. What kind of compression ratio are you running? That will help to determine when detonation might occur. It's impossible to just say, "set it at 34 and go", as many things are involved. Fuel type (octane) and compression are the big two.

 

I would be safe and start it at 32.* Knock is only audible when it is more extreme. On a scale of 1 to 10 you can only hear knock when it is at a 7 or so (10 is the worst). That is one of the drawbacks of carburated engines, they do not have knock sensing equipment.

Do you have aluminum or iron cylinder heads. If you have aluminum you can run a little more timing. GM found this out years ago. If you look at the binary files for L98 TPI's with iron heads Vs. L98 with aluminum heads you will see that the aluminum heads got more timing.