I had an 84 Z28 w/ the HO 305ci, T5 and 3.73s. I always loved the dual snorkel. It did ok, but nothing to write home about. I loved that car otherwise. Sad part is, I still remember the VIN:
1G1AP87GOEN181444. I think it ended up in Mexico after I traded it in on a 93 Z28 in Carlsbad, CA back in 95/96. I'd love to get it back if it's still stateside though. It never showed up again on Carfax...