Flex fuel sensor
It might be BS but I was told a shop here in the midwest fiqured out how to put a flex fuel sensor from a Silverado 1500 in a ZL1. They said it only took one wire hooked up to the ecm harness and all the fuel maps were already there for E85. Claimed it really woke the ZL1 up.
I know..I know, sounds fishy but........what if?