Maybe I will try these spark plugs sometime soon: NGK Laser Double Platinum Spark Plug 3573 NGK Heat Range 5

My truck had similar symptoms (at the beginning) worsening until coolant water got pushed out the overflow tank and showering out the tailpipe...
Head gasket was ok but the two center cylinders had small cracks in the head between the valves ~ Clearwater supplied a non jet valve Chinese head with complete hydraulic valve train...
Coolant leak & excessive oil consumption problems solved...
Dang miss-fire still happens sometimes mostly when shifting into 2nd gear and gently accelerating ~ WOT stops that mis-fire...
Hope to replace the Thermo Valve Sensor (Amayama supplied just hope it is correct part)
Filled tank with NON ETHANOL gasoline which has made a world of difference improvement in drivability and 95% miss-fire elimination..! Worth the $5.90 a gallon..!
Wishing you the best & easiest fix Sub...

Aloha ~ George