[Benson]

Tyler,

Is there any chance that you have a Model B timing cover? If so the timing on B cover starts at 19 degrees instead of zero. So 19 plus the 40 of stock dist is 59 degrees advance ... WAY too much!

The timing pin on the A cover is close to the timing cover mounting bolt at the 9 o'clock position vs the B cover where timing pin is closer to 10 o'clock mounting bolt.

I never ran a B timing cover with a stock A head so I do not know it the engine knocks at 1/2 advance in that configuration.

But a B cover with a "head with the large B" (5.2 to one) is WAY too far advanced. The HC head needs less spark advance than a stock head or it rattles and knocks.

A note about the spark lever position and HC head. I have run a "Large B" for 45+ years and it likes the lever about 1/3 to 1/2 around town and pulling slow speed hills and a little less than 3/4 MAX (28 degrees) above 50 MPH. (3/4 spark lever position is 30 degrees on stock dist.)

28 degrees is the max I ever run the spark with HC head and less advance at any speed if on a hard pull up a hill. You can hear and feel it pounding if too much.