Strange “dealer-installed” parts were being assigned AMC part numbers as racing continued. One was a front-suspension crossmember that allowed for bolting on a Ford Mustang suspension, which featured the antidive characteristics that Javelin suspensions lacked. Also, a front spindle became available that accepted Lincoln disc brakes, which Ford was using in Trans-Am for their superior cooling properties.
In analyzing the 290ci engines, Kaplan wanted a bit more stroke, but the blocks didn’t allow for any more throw. Working with the AMC foundry, retired 290-engine designer Dave Potter came up with a plan. First, 11/16 inch was added to the decks, requiring spacers for the intake manifolds. Then the foundry devised a way to cast the bottom end of the 390ci block, which used four-bolt mains, to the top of the 290, which only had room for two-bolt mains. The two combined changes allowed the use of longer, standard Chevy connecting rods.
In 1969, to lighten the cars, they were acid dipped (against the rules) and Team Javelin tried using fiberglass quarters in an illegal attempt to lighten the car. When the SCCA guys strolled into the pits with a magnet, steel quarters were quickly fastened to the chassis.
For 1970, AMC did the smartest possible thing, they hired the winners of the previous 2 years, Penske Racing with driver Mark Donohue. Penske was so determined to win that there was no Second Place finish bonus in the contract with AMC. When the news was announced at a press conference, Penske predicted the Javelin team would win at least 7 of the 12 races—a risky thing to be offering up having not so much as touched a Javelin race car. Penske was establishing how deep his determination was to win, even bringing back Peter Revson to race the second Javelin behind Donohue.