Not an L99, those are 4.3L LT1's. It's either got the good old 5.0-liter, with 175 hp and 265 lb.-ft. of torque, or the stronger 5.7-liter with 200 hp and 310 lb.-ft. I don't think either are LT based engines..see below:Originally Posted by blowfishRus6
The L05 (5.7) was introduced in 1987 for use in Chevrolet/GMC trucks in both the GMT400 (introduced in April 1987 as 1988 models) and the R/V series trucks such as the K5 Blazer, Suburban, and rounded-era pickups formerly classed as the C/K until 1996
The L03 (5.0) was the "low output" 5 L (305 cu in) (compared to the 305 TPI LB9). It produced 170 hp (127 kW) and 255 lb·ft (346 N·m) of torque (190 hp (142 kW) at 4,400 rpm and 275 lb·ft (373 N·m) at 2,400 in 1993-1995 GM trucks). This engine used throttle-body fuel injection. The TBI uses a unique injector firing scheme, for every rotation of the engine, each injector fired twice.
