In August 1974, at the error-plagued PRO National Challenge event on Long Island, Sox made some Pro Stock laps in a Don Hardy-built Sox & Martin Colt that had been put together for New York area racer Ronnie Lyles. There was also a little-raced, match-bash Colt the team had ordered from Logghe before the end of the S&M operation, which was sold to Nelson DesChamps in mid-1974.
In early 1975, when Larry Carrier suggested Pro Stock get a flat 6.75 weight break across the board, Sox bought the Lyles car with the intent of racing IHRA with it. his first appearance was in Lakeland, Florida, for their season opener, and he was joined by Bobby Yowell in the Billy the Kid/Stepp Colt at the next event in Rockingham, North Carolina. This was a '73 model that Yowell had debuted at the U.S. Nationals in late 1974, running in B/Altered trim. Unfortunately, with big-inch Hemi power, the cars were not competitive against their lighter-weight competitors.
Following Pomona in 1975, NHRA readjusted their weights again, trying to get the Hemi A-bodies, long-wheelbase Fords, small-inch Vegas, and Monzas on the same footing. But 1975 would not be a year for any strong Mopar showing in the Pro Stock division. Roy Hill, with Petty Engineering help, would put his ex-Butch Leal Duster into the NHRA and IHRA fields regularly, but he showed up in the late rounds only rarely. Larry Huff had won the '74 AHRA title dominantly in a Landy-assisted Dart Sport, but he too was frustrated in the new year. in IHRA, Ford and Chevy machines dominated in 1975.
In 1975, the Colts began to show their stuff in the Sportsman divisions, running primarily in the Altered classes of Competition Eliminator. In Hemi trim, Gene Dunlap was cranking off solid times in B/A in the Rod Shop entry, winning class over Don Carlton's Dodge Dart Sport at Indy (though losing to him during eliminations on Monday). Dunlap would move his car around between B/A and C/A based on his competition and conditions. Carlton was still in the infamous "wire car" A-body. In match race action, the Colts got faster-Sox blasted off 8.60s at 159 mph as he went up against the likes of Larry Lombardo in Jenkins' Grumpy's Toy in Saturday night fighting.
Roger Denney's Colt showed up at Pomona in 1976 to run B/A, where he beat Don Carlton's A-body. But by Indy, Carlton himself was at the wheel of a brand-new gold Rod Shop Colt, running below the 8.60 index with ease and beating the Pro Stock-style Mustang II of Scott Shafiroff to become the only repeat Indy winner from 1975. Tricked out with titanium and magnesium, Carlton's car was now capable of crossing the finish line in the 8.40s at better than 160 mph; again getting cries of unfair from the weekend warriors who made up a majority of the competitors.
Because of this, for 1977, NHRA decided to resurrect the old FX moniker and move the late-model, "used" Pro Stocks dominating Competition Eliminator into tougher index brackets on an A/FCX, B/FX, and C/FX classification. Carlton and his crew led by Clyde Hodges pulled the body off their gold car, lengthened the chassis to a monstrous 117 inches to achieve a massive engine setback, rebodied it in fiberglass, and stayed in B/Altered for the '77 Winternationals. Having made their point, this car was rebuilt closer to standard, the '76 gold body reapplied, and leased to campaigner John Zorian for match race use.
Also, by 1976, the Colts began getting some attention in Pro Stock, though not in NHRA. Unfortunately, this focus was not for the right reasons. Several were showing up at IHRA events, including one that had been built for the Competition team of DeSantis & Crider, which Roy Hill took to the Pro Stock final at the Pro-Am in Atlanta early in the season (Hill finished Fourth in the IHRA Winston points that year). But disaster struck at Bristol that June when Gene Dunlap in his Colt cracked up on Thursday evening. Rod Shop owner Gil Kirk made a quick deal to buy the Billy the Kid car as soon as the race was over. What he got was a pile of junk-driver Bobby Yowell had flipped that car on a qualifying run Friday morning! Soon after, Billy Stepp made a deal with Ronnie Sox, and the ex-Lyles Sox Colt was backed by Stepp for the rest of the season. Kirk ended up buying Denney's Hardy-built car, added Rod Shop logos, and it ended up with pilot Bob Riffle for the remainder of 1976 after Gene Dunlap stepped away from the driver's seat.