So .. how much damage? 97 sidekick seriously over revved

[fixkick]

ouch, double bad. almost worst case. near.
maybe the transfer case chain survived, but the engine is in big trouble.
we can work that backwards,
5.12 rear axle, 1:1 transfer, and at 60mph the stock engine turns 3000 rpm, in 5th. (overdrive .80)
so in 2nd gear, its 2 times faster , 6000 rpm. (assumes 60 was 60, and not 80) stock tires sized, larger tires, worse.
so that is max rpm spec on the engine, that be screaming its guts out. under the hood.
sure, you can start at low /no oil pressure as after all that is the sign of death or will be soon.
that lamp on can be mean oil pressure is 3psi or 0. (both are doom)

the stock engine with fuel pump relay pulled, can do 55psi just cranked, over, not started, with 10w-30 oil.
you could also change the oil see if chucks of babbit fall out bottom drain.

i bet big end rod bearings might be bad or bent rods, causing it.
the head runs off a .050" orifice in the head gallery preventing total pressure loss
in the event of total cam failure, (cracks in half, and falls apart,or seizes)

there will be damage, to what extent, be impossible to guess. (inspections only work on damage)

sorry for the loss. (best is to drop rear drive shaft, , even as one can hit a bump and either trans can bounce in to gear,
some folks tie the shifter's off, so that cant happen.

best regards.

you never said what both levers were set to, 5sp and tranfere case,

Sorry - transmission in 2nd .. transfer in 4H .. manual front hubs unlocked.

So I guess first step is try to check actual oil pressure and go from there.

Thanks