The Allard J2X is the most famous Allard. It was popularized when an Allard J2 with a Cadillac engine won third place in the 24 Hours of LeMans race. Allard subsequently introduced the J2X, which could be retrofitted with whichever engine the consumer desired. This one has a 331-cubic inch Cadillac V-8 engine rated at 255 horsepower, capable of staunchly, if perhaps not-so-agily, competing in any tournament of speed on or off the track.
A complete restoration was undertaken in 2010 by Steve Dennish of the Limeworks Speed Shop. The Allard features custom-ground camshafts, Stromberg 97 carburetors, and a Lincoln-Zephyr transmission. The running gear and body panels are original, as are the gauges and Brooklands windscreens.
According to David LaChance of Hemmings Magazine (2024), "this British bulldog with a heart of American iron is welcome on any race track, and offers a sure-fire way of standing apart from the crowd."