What fuel should I run in my 340?

I run 94 Sunoco in my cars with stroked engines.It all depends on your compression.Make sure cyl 5 and 7 plug wires are seperated good.These 2 are common for spark jumping,causing it to run bad.Good luck.

P.S I use asbestos sleeves over my plug boots,great for hedders too.
View attachment car pics 66 Dart 172.jpg