Suggestions on which plugs to go with

Holdener dynod a 5.3 LS with just about every single spark plug he could find. No single plug made a significant difference one way or the other. What to take away from it is, if your ignition system is up to snuff and the engine is healthy the plugs won’t make a damn bit of difference. Get the physical attributes right (thread size, depth, sealing (gasket or taper)) and get the heat range close, then fuckin send it!