<P> An even more powerful version, producing 465 hp (347 kW) and 610 lb ⋅ ft (830 N ⋅ m), of the 454, then dubbed LS - 7 (not to be confused with the modern, mid 2000s, 7 - litre Chevrolet Corvette engine that powered the C6 Z06), was also developed . Several LS - 7 intake manifolds were individually produced and sold to the general public by a few Chevrolet dealers as optional performance parts . The LS - 7 was later offered as a crate engine from Chevrolet Performance with an officially rated power minimum of 500 Gross HP . </P> <P> In 1971, the LS - 5 produced 365 hp (272 kW) and 550 lb ⋅ ft (750 N ⋅ m), and the LS - 6 option came in at 425 hp (317 kW) and 575 lb ⋅ ft (780 N ⋅ m). In 1972, only the LS - 5 remained, when SAE net power ratings and the move towards emission compliance resulted in a temporary output decline, due to lowered compression, to about 270 hp (200 kW) and 468 lb ⋅ ft (635 N ⋅ m). The 1973 LS - 4 produced 275 hp (205 kW) and 468 lb ⋅ ft (635 N ⋅ m), with 5 hp (3.7 kW) and 10 lb ⋅ ft (14 N ⋅ m) gone the following year . Hardened valve seats further increased reliability and helped allow these engines to last much longer than the earlier versions, even without the protection previously provided by leaded fuel . 1974 was the last year of the 454 in the Corvette, although the Chevelle offered it in the first half of the 1975 model year . It was also available in the full size Impala / Caprice through model year 1976 . </P> <P> General Motors introduced EFI in 1987, which was found on GM 2500 and 3500 trucks . The 454 EFI version was rated from 230 hp (170 kW) to 255 hp (190 kW) and from 385 lb ⋅ ft (522 N ⋅ m) to 405 lb ⋅ ft (549 N ⋅ m) of torque . GMC continued to use the 454 EFI until the new Vortec 7400 version arrived in 1996 . </P> <Ul> <Li> 1970--1976 Chevrolet Caprice </Li> <Li> 1970--1975 Chevrolet Chevelle </Li> <Li> 1970--1975 Chevrolet Monte Carlo </Li> <Li> 1970--1975 Chevrolet El Camino </Li> <Li> 1971--1972 GMC Sprint </Li> <Li> 1970--1974 Chevrolet Corvette </Li> <Li> 1987 GMC Suncrest </Li> </Ul>

How much torque does a 454 big block have