Unless you are trying to gain some height, do not change the preload. King sets them up perfectly before they go out the door. If you are looking to gain some lift, just add a leveling kit.
I have a Whipple on my 18 with also a cam and heads. Only upgrades I did was LT4 injectors and my fuel system is maxed out. If you bought the complete kit from Whipple and don’t plan on doing anything else, you won’t need to change anything. Also, my kit came with new plugs
I’m in Orange County right below you. I have Texas speed headers with no cats. Before I had my rear monitors turned off, I ran 90 degree o2 extensions, CEL never came on. Had it inspected twice so far by Barton Birks in Newburgh with no issues
It wasn't that bad to make. I bought a universal gauge pod and a new panel just in case I messed up. Molded it in with modeling clay to get my form then just fiberglassed over that. Bondoed, sanded smooth, primed and painted.