AMC Gremlin 401-XR
Powering some of the most successful American muscle cars and police fleet vehicles of the 70s, including the AMX 401 and Police Matador, the AMC tall-block was known for its power and dependability. The AMC 401 represented the best that the AMC tall-deck formula had to offer from 1971 to 1978.
With AMC taking the SCCA Trans-Am championship in 1970, the company was starting to look like one of the few manufacturers who were still interested in catering to young performance buyers, and Randall AMC would quickly become the go-to shop for the most potent American Motors hardware.
Aside from some badging, there was little to help discern a Gremlin 401-XR from a garden variety Gremlin X. While that undoubtedly upped the sleeper factor for this rare machine, it also did not stray very far from the Gremlin's economy car origins, and the aesthetic just couldn't generate the same level of "cool factor" for most buyers who were cross-shopping the model with the Roadrunners, GTOs, and Firebirds of the day.
AMC built a total of 671,475 Gremlins from 1970 to 1978, and some of the obvious features collectors look for are V-8 engines, manual transmissions, and the sporty “X” package. But perhaps the most desirable option out there is the Levi’s jeans interior.
Randall AMC dealership in Mesa, Arizona, apparently did not get the message though. In 1972, with the endorsement of AMC corporate, the performance dealer would unleash the most potent “factory” Gremlin ever produced — the 401-XR.
The Randall Formula
If the power to weight ratio was becoming an issue with model bloat toward the end of the muscle car era, the Gremlin served as a utilitarian response to the problem. With a 96-inch wheelbase, this diminutive compact weighed in at roughly 2600 pounds depending on its configuration, which made it nearly half a ton lighter than a ’71 Ford Mustang or Dodge Charger.
AMC’s factory V8 package included the beefier suspension and brakes that a car with this sort of power to weigh ratio would need, so for under $3K, buyers could get that bigger engine in an otherwise unmodified 304 car and run 13-second quarter miles right off the showroom floor.
In spring of 1972, Car Craft put a well-optioned Gremlin 401-XR through its paces. Outfitted with the optional ignition, exhaust, and camshaft upgrades, the magazine posted a quarter mile run of under 12.3 seconds — more than a second and a half quicker than a “base” Gremlin 401-XR.
https://www.streetmusclemag.com/features/muscle-cars-you-should-know-amc-gremlin-401-xr/
https://musclecarclub.com/ultimate-amc-401-engine-guide/
https://duckduckgo.com/?q=amc+gremlin+401+v8&t=opera&ia=web