....You need a wideband and a great understanding on how to tune a carb..
Thatís the secret. I drilled and tapped my Speed Demon so I could change the IFRís, all air bleeds, the PVCR and I played with the emulsion circuits. I have about 29* at idle and I run as much vacuum advance as possible. I also found using the HVC ll coil a must as a Blaster SS didnít work nearly as well.
The custom Straub Tech cam also helps a lot.
I found most of the info to do this on this forum.