Paul Frost, mechanic for Billy Stepp, was prepping a Colt as well, but other Colts were being built for non-Pro Stock use, some for the now defunct Modified Compact class with race-worked OEM fours, and others with a variety of V-8s for Competition Eliminator. However, a rash of accidents in Pro Stock began to get the attention of SEMA by mid-1973, which had no rules per se on Pro Stock chassis design yet. Indeed, returning driver Bill Flynn's new Logghe Colt flew at Epping almost as soon as it was done, and the likable Yankee Peddler was in the hospital for a while after the fact. Hedrick's newest Super Shaker suffered the same ignominy soon after his car was completed. Former Mopar racer, Irv Beringhaus, was less fortunate when the ultra-lightweight Pinto he had switched to disintegrated at the '74 AHRA season opener in Phoenix, and he was ejected and killed.
In April 1973, Carlton drove the new Ron Butler-built Motown Missile Duster with the new D5 heads to an 8.98 time at the IHRA race in Rockingham, an average of 9.007; at the same event, Dick Landy clocked an unreal 152 mph on a time trial, and the need for the Colts again seemed to fade. By the time the tour hit Bristol that June, Larry Carrier's guys had shifted the weights to 6.40 small-block/6.85 big-block and Hemi to fix the dominant Mopars. nonetheless, Butch Leal took his Butler-worked Duster to the top of the field with 9.22, followed by Nicholson's Pinto at 9.23, and Carlton at 9.26. Carlton won the rain-out on Monday over Nicholson, then went to the NHRA Springnationals to score Chrysler's first win in almost a year, beating Leal 9.40 to 9.44 in the final. Leal followed up that showing with a runner-up at Englishtown to a resurgent Jenkins, and wins at the Pop Hot Rod meet in Michigan and the Molson NHRA race in Sanair, Canada. Things were looking up for the Mopar troops, despite NHRA's stout weight rules and the Fords.
So the factory decided the Colts were not going to get backing for 1974 after all, choosing instead to go with the Duster and the new Dart Sport since there was no Plymouth equivalent to the Colt. the plan since getting involved in drag racing over a decade prior had been to sell American performance cars, and the overall situation was pretty solid. Leal had blasted to an unreal 8.88 in AHRA trim at Orange County in September 1973, the quickest time and speed in that sanction's history, while winning the event crown. In fact, Dick Landy's consistent efforts had netted him the '73 AHRA World Championship in Pro Stock. Meanwhile, Carlton had sewed up the IHRA crown by going to all eight finals and winning five of them. As some expected, Wayne Gapp and Jack Roush took the NHRA champ's crown in a Pinto, the final year of the era when all such titles were decided solely by winning the World Finals.
Then NHRA announced its Pro Stock rules for 1974, and things got crazy. Now the rules were a combination of both wheelbase and cubic-inch regulations. Hemi cars and their Ford SOHC counterparts stayed at 7.0 pounds-per-cubic-inch regardless of wheelbase. cars measuring over 105 inches with canted or inline-valve engines (including the Boss and Rat motors) could weigh in at a scant 6.45. Cars under 105 inches with canted valves mills were at 6.75 (Rat and Boss motors), while in-line small-blocks (Chevy, MC, and Mopar wedges) were at 6.65, as were big-blocks other than the Hemi combinations listed above. The result-by June, Gapp & Roush got a hold of a 108-inch, four-door Maverick that Don Hardy had built and ran it on the small-block, long-wheelbase break.
At this point, Chrysler decided to boycott NHRA Pro Stock altogether. Butler put a '65 Hemi Belvedere together for Leal that was the scourge of SS/B, Sox was back in a '68 Hurst-type SS/A Cuda, and Landy was in an SS/DA '70 Hemi Challenger. In match race form, some A-body Pro Stock Mopars were now getting all-aluminum fuel block packages like the Milodon that Herb McCandless used to blast off an incredible 8.51 at 159 mph at Atco late in 1973. At 95.3 inches, all Hemi Colts were at the 7.0 break, while the 108-inch Duster/Demon package could conceivably go at 6.45 in wedge form, especially with better heads (the W2 would be the answer to this, but development was still a year away from even being completed). One frustrated racer told writer Rick Voegelin, "It really upsets me when I think about it. These rules must be decided over a Scotch bottle."
Soon after, Chrysler proposed an interesting concept: run everyone at a flat weight break using true wedges and 105-inch-or-larger wheelbase (good-bye Hemis...and Pintos, Vegas, and Colts). With no takers on the plan, and the factory big dogs hunting in the S/S Sportsman classes, a few Hemi Colts began to finally trickle onto the nation's raceplants in match race trim. mid-1974 also found Sox & Martin agreeably ending their Chrysler deal, and Buddy Martin leaving the sport to pursue other interests.