These engines have WELL KNOWN piston slap and lifter issues. Have owned 10 LSX trucks last 20 years !! I would skip the "thin" 5W30 especially with us going into HOT summer months soon !!!!!!!!
I would go with a nice Mobil 1 10w30, Valvoline Full Synthetic or Pennzoil platinum oil's. And @ 53K miles I would stay away from the High mileage stuff unless it was sitting for years and already leaking oil ??
I also own a 01 5.3 LM7, but with 200K miles and been using Castrol Magnatec 10W30 with GREAT results !!
Sadly this oil was discontinued last year

I will be switching to Valvoline Full Synthetic once my Magnatec supply runs out
P.S If you ever have low oil pressure/knocking noise replace your oil pump pick up tube O ring ASAP !!