93 mixed with e85 at 40-50% ethanol to start. Will reduce alcohol content from there as I get it dialed in.

Not concerned if it can't run well on just 93 octane and I suspect it won't.

If I decide it needs to at some point I can swap out the head gaskets from the .027's I'm starting out with.

69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700