water mixture help?

[hotrod]

Unfortunately WI tuning is largely an experimental process. I can't give any hard and fast numbers for you as I have never tuned that engine with WI.

That said ---

Yes definitely go to a colder plug, might even go 2 steps cold if you can find them.

I'd probably start by dropping about 2 deg on the spark advance.
Too much spark advance causes huge increases in cylinder pressures and temperatures. If that does not solve the "plug eating" then I'd suggest dropping to a 50% water/50% alcohol mix and make a run and then pull the plugs to see whats happening.

Dropping to straight water would definitely be the safest approach, then gradually add back in alcohol step by step.

Just be aware that your current setup is on the ragged edge, so back off a bit, and then go slowly and carefully in a step by step process.

Larry