Always a good idea to have everything on hand to pull a head. I wouldn't worry too much about bottom end stuff, it's very rare that they ask for a piston/rod unless you are crazy fast, killing a record, or get protested. I don't think they pay a lot of attention to a "new" car except for safety. If you go 1.30 under on your first pass, that might be different...
Be sure to have enough removable ballast to adjust your weight to account for scale variations, and make sure the ballast is properly attached, they look for lose stuff.
Make sure you have an easy way to draw fuel for fuel check... that is one thing that is unique to Stk/SS.
I think you'll like stock/SS, especially in Div 2. There are a lot of really nice, friendly guys (and a few gals) in the classes and most of them treat us Ford racers as equals (well almost all are nice, and Fords almost equal
). Most of the tech guys are friendly and helpful too. We won't mention the div director, oops, I just did...