... given all that, is there a way to take the Denali 6.2L (or starting in 2018 with the Tahoe RST package) up to the same output as the 'vette, without adding a supercharger?
ECM tune & TCM tune would be the biggest bang for the buck in terms of getting a GMTK2xx 6.2L closer to 'vette 6.2L output parity.
If you specify that you'll never use 87 octane , or 87
& 89 octanes, the engine tune can be considerably improved.
As for the TCM, GM programs it to maximize MpGs, meaning less fun.
A TCM tune may lower the peak possible mileage by 2 or even 3MpG, but the transmission will become more responsive, improving Smiles per Gallon.
I'm still confused as to why more of y'all ain't gotten your vehicles tuned yet ...