A member here went 13.6 on slicks/skinnies with an intake/headers/open downpipe/tune.

Yeah, totally possible.

I went 13.8 @ 99-100 each run...on street tires with ported manifolds/3" DP/180*/plugs/wires/CAI/1.84 Roller Rockers...prolly would have gone around 13.6-13.7 with a decent tune though.