
all I wanted was for my LTG to run a bit cooler

I have built some radical LS/LT/SBC cars from scratch w excellent cooling.
This has me baffled.

Q. Is your experience like mine?
on Cali 91 Octane the motor pings on transition and acceleration at full temp
But does not ping at cooler temps
100% stock it does this.
Purchased Gates 180F Thermostat 34717
post install, temp vary alot 182 to 210.
Fan is blowing full blast via HPT
But radiator to thermostat hose is cold
radiator is blowing luke warm
Tested the thermostat in a pot on the stove with Pro IR gun
free of housing it moves its push rod at 180F
in the housing it barely cracks the open
turns out the push rod is shorter than OEM
order a second 34717 ...same thing
*the supplied housing gasket is also 100% wrong
So I used a simple BB dropped into the housing to extend the rod
retest... works great
Back in the car same-ish thing
much longer warm-up time, temps vary alot 175 to 205.
Fan is blowing full blast via HPT
But radiator thermostat hose is cold
radiator is blowing luke warm
All of this was done;
monitoring the KR temps and Fan speed in HPT.
3-or 4 heat cycles with the coolant topped off.
checking the same drive home from work
GM list the stock thermostat * 2-stage thermostat (90 and 105 C) 194 & 221F
Q. what exactly does 2-stage thermostat mean ?
Q. does the belt driven water pump have full flow all the time ?
Q. am I missing something basic ?
Q. is there a hidden cooling system bleeder , somewhere ?