I'm pretty sure that I have built up carbon deposits in my 1986 corvette convertible with aluminum heads. I get noticeable pinging when hot and accelerating even with 93 octane gas.
My plan is to gradually mix in some E85 gas (since I already have E10) to bump it up to perhaps E35 to both increase the octane rating and to clean up my engine combustion chamber, valves, fuel injectors and pistons. This would be only maybe one tank full. The racers swear by E85 because it runs cool and keeps the engines really clean. I've been told that the E10 already would have affected any parts that might dissolve and I have been running E10 for 10 years and no rubber problems.
I understand that this may change my tuning but would it make it bad enough where it wouldn't run? Hoping to find E85 enthusiast to chime in.