The LR4 is the 4.8.

The 5.3 is known by many names:

Vortec 5300 5.3L V-8 (LM7/LM4/L59)
Vortec 5300 Gen IV V8 ( LH6 )
Vortec 5300 V-8 (L33)
An all-aluminum version of the Vortec 5300 V-8 (L33) engine is available in Chevrolet 1500 Silverado Extended Cab and GMC Sierra Extended Cab models equipped with four-wheel drive and the short box. The 5.3L V-8 produces 310 hp (231 kw) and 330 lb.-ft. (447 Nm) of torque.

Constructed with an aluminum block and cylinder heads, this version of the Vortec 5300 V-8 is 100 pounds (45.4 kg) lighter than versions with an iron block. Reduced mass enhances handling and balance, as well as fuel economy.