Does race gas benefit the ls3?
 

Only with boosted applications. Being I can only get 91 octane here, but can get 100, I do a mix of 91 and 100 to get an average of ~95 and running an eforce at about 10psi.

Any mods, tune, etc? What are expected temps? Chances are good that 93 will be fine. Don't expect anything more to help if you currently don't have any KR.

My opinion ....

If you have [not] increased the compression of the motor and are [not] running any boost, premium grade gas is all you need especially with the cool ambient air temps you have at this time of the year.

No HP gain by adding race gas to the mix.

Increasing octane will do nothing more than decreasing your wallets' contents. Unless the car has increased compression over stock or you've installed a power adder you may actually LOSE performance by putting higher octane in the vehicle.

Higher octane does not equal more power. Octane rating pertains solely to the fuels ability to resist knock (pinging).

U.M.

Stock LS2 with higher compression runs it best on 93 octane.

The stock LS3 with lower compression that the LS2, only needs an octane rating of 91 to run it best instead.

The OP has boltons, so I'd assume a tune also. If it was stock, there's not enough difference to notice. The tune and high IAT can make a LS3 knock even on 93.

The OP has boltons, so I'd assume a tune also. If it was stock, there's not enough difference to notice. The tune (advance) and high IAT can make a LS3 knock even on 93.

Since you have bolt ons and we are assuming a tune, we can only speculate that you do not have knock retard with 93 octane. If you do have KR present, then yes higher octane will benefit. You should log your runs to answer your question.