ok heres the deal i have an 96 lt1 w/ 161,000 miles, ive change the opti, coil, wires, plugs... but it still misses between 5k - 6k... now some one mentiond it could be my valves but ive never adjusted them since i had the car....

 

anybody!!!

BTW it only does it at WOT

 

My 94' did that until I replace the stock coil with an MSD Blaster coil....Since you already replaced that part, Im not sure...Could be your Fuel Pump? Just a thought

 

i have a walbro 255lph in there now, that was put in over 2yrs ago.. but its driving me batty...

 

Fuel filter may need to be replaced?