Got detonation issues w/ 331, could it be my 30's near their max???

Well 19's can handle like 300 at the flywheel, so theres no reason why your 30's couldnt handle 410 at the fly. Before you do anything, you should some how see what your A/F ratio is across the board. This will answer your question before you go replacing expensive stuff.

30s should be fine at that power level. What's your compression ratio?

I'm running 30# FMS injectors on my combo...see sig. Anyhow, it would seem that if it were a fuel delivery problem, it would have showed up on the first dyno tune. Your problem appears to have developed over time and suggests a different situation. If you have unburnt fuel leaving carbon deposits in your combustion chambers, it raises your compression ratio over time, leading to an increasing tendency for predetonation. So, what do you do...raise the octane level of the fuel, back off on the timing...this in turn, only serves to aggrevate the problem. Sure, it helps in the short term, but as you have found out, the problem resurfaces later on.

My suggestion is to run some fuel system cleaner and some engine oil system cleaner through the engine with your next fill-up and oil change. Talk to your tuner in regards to the possibility that your engine may actually be tuned a little RICH,...or...that you may have a weak ignition system that isn't burning the fuel as it should. A wide-band O2 sensor should tell the story. Perhaps it's time for another visit to your shop.

My .02

i agree with 86 cobra, i dont think its the 30s, they should work good.