GMC Straight-6 engine

GMC as a marque really only "owned" two engine designs, the straight-6 and a V8. GMC used many engines from other GM divisions, as noted below.

Non-GMC engines

207

In 1935 and 1936, GMC used Oldsmobile 213 L-head engine

230

For 1937 and 1938, GMC used Oldsmobile's 230.

223

In 1938, GMC used Pontiac's 223.

235

GMC used the 235 in³ (3.9 L) Chevrolet Straight-6 engine as their base truck powerplant in the 1950s in Canada, not USA.

261

The Chevrolet 235 was bored out to 3.75 in (95.2 mm) to displace 261 in³ (4.3 L). This engine was offered as a step up from the 235 starting in 1954. It was replaced by the GMC V6 engine in 1960.

292

From 1963 through 1978, GMC had its own distinctive version of Chevrolet's straight-6, the 292.

GMC engines

228

GMC replaced the Pontiac 223 with their own 228 in³ (3.7 L) 228 in 1939. This overhead-valve engine was produced through 1953.

236

GMC also developed an OHV/pushrod engine in 1939. The 236 in³ (3.9 L) 236 was the first, lasting through 1955.

248

Those same years (1939-1955), GMC produced a 248 in³ (4.1 L) engine, the 248, which was similar to the 236.

256

The 256 in³ (4.2 L) 256 was different from the 236 and 248. It was also an OHV/pushrod engine, and was built for just two years, 1940 and 1941.

270

The last GMC-only straight-6 was the 270 in³ (4.4 L) 270. It was produced from 1941 through 1962 and was an OHV/pushrod engine.

302

The 302 GMC inline six was produced from 1952 to 1960 and is a 4" bore and 4" stroke engine. It was originally designed for the GMC military M135 and M211. It was used in military 2.5 ton trucks with the HydraMatic transmission, however the engine was a sealed engine for snorkle/submersion use, had an electric fuel pump, and other features such as a deep sump oil pan. From 1952-1959, GMC manufactured the civilian 302 engine which was not sealed, had a mechanical fuel pump, and used a "standard" oil pan. This engine is popular with hotrod enthusiasts because it delivers tremendous power for an inline six engine, is truck built with a heavy cast block, and can take quite a bit of abuse.

ee also

* GMC V6 engine
* GMC V8 engine
* List of GM engines