I totally agree but my performance shop in Houston, who are LS record holders at the Texas Mile, said put on any aftermarket valve cover and get ready for oil leaks. I pushed them hard and they basically said, go ahead, don't listen to us. I wish you a different result.
2017 SS - RPG A6, roof, spare: Ceramic Pro, Livernois Stage 2 build w/ Stage 2C-HL cam, LS3 heads to Stage 2, RotoFab, Kooks 1-7/8 LT, green catted, Borla 2.5" XR1, ZL1 TC, BMR
2017 SS - OBM M6, no roof, spare: Ceramic Pro, RotoFab, Kooks 1-7/8 LT, green catted, Borla 2.5" XR1 mufflers, BMR tunnelbrace
2018 Tahoe RST - Tungsten LT1 w/Borla (350RWHP) and Brembo's
1987 Buick WE4 purchased '87; sold '97; repurchased 11/2017. Frame off underway, finish 6/2019(revised)