While on the subject of HEI.

I just purchased a 67 F-bird with HEI installed. Runs great but at cruise speed, light thottle, I have a rattle which I believe to be spark knock. I am using premium fuel. Anyone have any thoughts?

Also: I'd like input on the following.

1. On a stock 326 2V, will the initial timing of 6 degrees remain the same?

2. Can i use the same type plugs and what would the plug gap be?

3. What degree of total timing does the 326 like?