Chevy Small Blocks 1981 to 1995 Number-8
Four inch bore family
The 350 continued
The LT-9 350 variation is often known by its VIN code as the “M code 350”. This 5.7 liter engine is in the K20 and the K30 pickups as well as step-vans and motor homes on the P30 chassis marketed from ’81 to ’86. The engine has a four bolt main bearing configuration with the factory specs listing it as developing 160 bhp at 3500 RPM and producing 250 lb.-ft. of torque at 2800 RPM when equipped with the Rochester Quadrajet carburetor.
In the 1982 model year the only engine available for the Corvette is the L83-350 with 9:1 compression and is coupled to an automatic transmission only will give up 205 bhp and offers 285 lb-ft of torque. The power option in ’82 is a twin throttle body fuel injected version called the cross-fire. There was no production model Corvette in ’83 and therefor no L83 in that year.
The first of the generation four is the new L98 for Corvettes; this 350 is in show rooms for the 1985 model year. The basic equipment tuned-port fuel injection (TPI) allows this version to produce 230 bhp in both ’85 and ’86 but for ’87 through ‘89 it is bumped up to 240 bhp but with the optional 3.07:1 rear axle ratio (’88-’89 only) the engine will develop 245 bhp. The L98-350 d the option of aluminum heads in 1986 , with “D” ports added for the 1987 models and this head option was available for the Corvette until the end of its run in the Corvette in the 1991 model year.
From January 1987 until 1992 the L98-350 is an option for the Firebird and the Camaro with the basic ‘87 edition producing 225 bhp (168 kW) while offering 330 lb-ft of torque but the power option would put out 245 bhp (183 kW) offering 345 lb-ft of torque with a modified hydraulic roller camshaft. For the 1990 model year the output is increased with the cylinder compression upped to 9.5:1 for the Camaro and Firebird while in 1990 the ‘Vette with the same L98 engine offers 10:1 compression.
In the 1987 model year Chevy, GMC, and all the rounded C/K class of trucks including the four door crew cab units can be equipped with the L05 version of the 350 engine, as well, the recreational Suburban and the K5 Blazer have this engine. Other G.M. products with the L05-350 as an available option from 1990 through to 1993 with the L05 production ceasing entirely in 1996 include the Buick Roadmaster, Cadillac Brougham, Cadillac Fleetwood, Caprice LTZ, Caprice (wagon-an option), and the AMG Hummer H1 for `95-`96. From the 1994 model year until `96 the L05 is replaced by an uptown version called the LT1 in all GM `B`bodies while in the final year the Vortec heads are used in the 1996 G38.