IMO, SLP would be a better filter as anything SLP did to the Camaro during production, GM warrantied it.
K&N has holes in it - look through it against a light.
My PO installed a K&N filter in the filter box of my SS, and I replaced the filter with an AC/Delco paper filter.

 

open filters i see on all the new engines like the camaro mustang,local dealer says they hate to see the open filter couse they need to be changed an cleaned alot more often,an that guy who forget an dont change them often ,end up with throttle body issues an lots of dust an dirt in there ,can couse engines to fail,it depends on how there set up too,

some of the newer cars have them towards the center of the engine ,away from the front ,that gets all the dust an dirt ,those that drive on dirt roads just a little ,not good .so most cold air instakes are a rip off unless enclosed mostly allowing the filter to get the dirt an dust

the cone filters need checking often an replaced or cleaned 4 times a year or more ,again most dealers dont recomend them ,the newer ones are better couse they have like 3 feet to the cone allows for flow without getting dirt in ,those that just bolt a filter to the throttle body are at risk of to many particals getting in the engine

 

The oil on the K&N is unfriendly to MAF sensors. I use an Airaid oil free cotton filter (4 inch tall) on my 69. Carb stays clean and no oil residue. The design that offers the best linear air flow and CFMs is the way to go.