Any Pertronix experts here?

Just went and look at the PDF for that dist.. and it says .6 or higher, not just .6..

"The Flame-Thrower billet distributor can be used in conjunction with most ignition
coils rated at 0.6 ohms or greater. For optimum performance purchase and install a
Flame-Thrower high performance coil"

https://cdn.shopify.com/s/files/1/0247/6913/4628/files/D141710.pdf
I'm using the flame thrower 1 coil with mine.. runs fine so far. Are you running boost or high compression?