American Motors built its own V8 from 1956 to 1991, and the family grew through nine AMC V8 displacements along the way. The story starts with a 250-cubic-inch engine for 1956. It ends with a 360 still working under Jeep Grand Wagoneer hoods in 1991, years after Chrysler had bought AMC.

The engines came in three generations, spread across 36 model years. Here they are in the order they arrived, with the ratings and dates the records support.

1. 1956–1961 AMC 250 V8

The 250 was American Motors’ first in-house V8. David B. Potter led the engineering, while engineering vice president Meade Moore oversaw the project. It used a deep-skirted cast-iron block, a forged crankshaft with five main bearings, and 4.75-inch bore spacing that the next design kept.

For the 1956 launch, it had a 3.50-inch bore and a 3.25-inch stroke. With 8:1 compression and a Carter two-barrel, it made 190 hp at 4,900 rpm on regular fuel, according to Mac’s Motor City Garage. Dual exhausts came standard. AMC built the 250 from 1956 through 1961.

2. 1957–1966 AMC 327 V8

Next, AMC opened the bore a full half-inch to 4.00 inches, and the result was 327 cubic inches. With a four-barrel and 9:1 compression, Mac’s says it made 255 hp. AMC had also planned Bendix electronic fuel injection for it, but canceled the system before production.

The 327’s showcase was the 1957 Rambler Rebel. According to Mac’s history of the Rebel, AMC built exactly 1,500 of them at a $2,786 list price. Motor Trend timed one at 7.5 seconds from 0 to 60 mph. Later, Kaiser Jeep used the Rambler V8 in its 1965–67 full-size Jeeps under the name Vigilante.

3. 1963–1966 AMC 287 V8

When the 250 left the lineup, it left a gap below the 327. So, in the middle of the 1963 model year, AMC filled it with the 287. Unlike the 327, it came only with hydraulic lifters and a two-barrel carburetor.

The AMC V8 engine reference also says AMC built only two-barrel versions and kept the 287 in production through the 1966 model year. Then the whole first generation ended with 1966, according to Mac’s. Its modern replacement kept the old 4.75-inch bore centers, so AMC could reuse the machine tools.

4. 1966–1969 AMC 290 V8

The 290 opened the second generation. It arrived partway through 1966, with a 3.75-inch bore and a 3.28-inch stroke. In fact, the Auto History Preservation Society says it was lighter than Chrysler’s 273 and almost the same weight as Ford’s 289.

Rambler introduced the Rogue in ’66 specifically to show off the new 290 “Typhoon,” as Curbside Classic puts it. That account gives the engine 200- and 225-hp versions. The higher rating came with a four-barrel. Meanwhile, the AMC V8 reference says AMC built the 290 through the 1969 model year.

5. 1967–1969 AMC 343 V8

Later in 1967, AMC added a bigger bore to make the 343. It kept the 290’s 3.280-inch stroke but used a 4.080-inch bore. Its job, at first, was to move the larger AMC cars.

According to the Auto History Preservation Society, the 343 made 235 hp with a two-barrel and 280 hp with a four-barrel. Moreover, the society notes that AMC rated its engines with all accessories attached. Once the 280-hp version reached the Rogue and Rebel, AMC had muscle cars of its own.

6. 1968–1970 AMC 390 V8

The 390 arrived with the Javelin and AMX for 1968. AMC raised the bore to 4.165 inches and the stroke to 3.574 inches. Even so, the block’s deck height and outside dimensions stayed the same as the 290’s.

The Auto History Preservation Society calls the 315-hp rating conservative, and points to its 425 lb-ft of torque as the better hint. Then, for 1971, the 390 grew into the 401, according to SlashGear’s guide to AMC’s later V8s.

7. 1970–1981 AMC 304 V8

For the third generation, AMC lengthened the 290’s stroke, and the 290 became the 304. The AMC V8 reference dates the 304 to 1970 and rates it at 210 hp gross for 1970 and 1971. Jeep then put it in the J-series pickups and SJ Wagoneer for 1971, and in the CJ for 1972.

SlashGear also quotes Jeep Tech on the drop in output. By its figures, the 1971 304 made 210 hp and 300 lb-ft, but by 1980 those numbers had fallen to 125 hp and 220 lb-ft. Finally, AMC dropped the 304 from its option list in 1981, SlashGear says.

8. 1970–1991 AMC 360 V8

The 343 became the 360 the same way the 290 became the 304. It first appeared in the 1970 AMX, Javelin and Rebel, according to SlashGear. In the 1971 Hornet SC/360, a four-barrel carburetor raised output to 285 hp.

The 360 then moved into Jeeps, beginning with the J-series trucks for 1971. Chrysler bought AMC in 1987, yet the engine stayed on as the standard V8 in the Jeep Grand Wagoneer through 1991. That makes it, in the AMC V8 reference’s words, the last AMC V8 to be manufactured.

9. 1971–1978 AMC 401, the largest of the AMC V8 displacements

The 401 topped the range. For 1971, AMC offered it in the Javelin, Matador and Ambassador. It also went to Jeep’s Cherokee, Wagoneer and J-series trucks for 1974.

The AMC V8 reference rates the 1971 401 at 330 hp gross. Similarly, SlashGear’s list of 401-powered vehicles gives the Javelin version 330 hp and 430 lb-ft. AMC even sold the engine to International Harvester for its 1973 and 1974 Travelall and Light Line pickups. The 401 stayed in production through 1978.

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This article was created with the help of AI and was reviewed and edited by Fast Lane Only editors before publication.