I guess my question would be based on a mixture of materials, temperature, and compression.
On an carburated engine, 96mm bores and pistons, and modified 1.7 heads.
What plug heat range is proper for the type IV with approx 9lbs of compression?

My concern are thermal issues and damage to the pistons, running hotter than necessary.
I've read about pros and cons from CD ignition systems, to Nology Systems.
I have not found any discussion about heat range underload on air cooled motors.
My early 911 with its' CD box and new stock wires ran fine.
On my '73 914, I ran stock wires, Bosh Blue Coil and Bosh plugs with no problems.
I have never burnt a hole in my pistons.
A year or so ago, my son gave me Nology wires with new coil for a Xmas present.
My concern is not soild core spark plug wires, because I ran them on my '67 Malibu, back in the day...
My concern is increased spark and temperature range of the plugs supplied, with an air cooled engine.
Since I'm not out the money that they cost, and I am not running EFI, and don't have an ECU, what would be the problem, if any ?

You're probably gonna need at least one heat range hotter than stock because carbs run so fat, and because modern "smog" fuels run so crappy.

The Cap'n

...in the South East, pumps display 1% to 10% Ethanol...
Does this mean the reduced energy and slow flame propagation ?