Modern quality control was worked out by W. Edwards Deming, Joseph Juran and others at U.S. War Production Plants and had a huge impact worldwide in the reliability and durability of everything (engines, cars, planes, food, appliances, etc.-especially complex products like electronics.)
Electronics for that matter make a lot of large and small advances in technology, materials, testing, lab equipment, and the demand ("hang the cost, the government will build a vast factory immediately and grab talent for your staffing") allowed an almost new industry with tens of thousands of employees, especially clustered in LA and would later be called Silicon Valley given Stanford and CalTech's major roles. That's a really big impact for communications, computers, avionics, television, medical equipment, satellites, sensors, factory automation/machine controls, etc.. You'd have lots of difference in the ATL from ours just from a much smaller and costlier electronics industry in the 1940's-1960's.
The interstate highway system would either remain the 1930's Lincoln Highway system (without Cold War concerns, postwar prosperity, Eisenhower as Pres who knew the road system personally, and the exposure to the German's autobahn system) or come about in a far slower and more piecemeal connector on the busiest highways or the ones with the greatest political clout in Congress rather than a rational national system and that would have huge ripples in which cities and states prospered or stagnated as well as the impacts of interstate trucking, containerized/intermodal shipping, vacationing, and commuting patterns.
Mass produced construction methods were considerably refined during the war so vast new suburbs would have taken decades longer to build and kept housing quite a bit costlier or set expectations to old brownstones instead of suburban tract homes. The building industry overall is America's largest so that would have all kinds of ripples in employment, building materials and furniture/applicance mfg., mortgage lending, and even politics.
Mass production of ships by Henry Kaiser and Stephen Bechtel to outpace U-Boat sinking rates and keep the Allies supplied revolutionized ship construction techniques and methods, dropping their cost considerably and building a modern maritime fleet for world trade. So without this the world has a much older and lower capacity fleet dominated by Great Britain that might inadvertently hold it's colonial empire together far more than OTL.
Other fairly minor wartime inventions in the grand scope of things:
cheap and easy submachine guns (British Sten, American M-3)
bazookas
large, guided rockets with better fuels
proximity-fused shells, particularly anti-aircraft, war only application but made a huge difference, air to air missiles,
useful sonar, aircraft-borne radar, longer range radios
nuclear breeder reactors and uranium enrichment-peacetime applications for nuclear energy power production and shipboard propulsion systems
freeze-dried and frozen foods (Clarence Birdseye) and that was driven by the war effort and food shortages/transport needs (knew a gal who worked for him back then)
Jeeps which considerably usher in 4 wheel drive SUV's, the amphibious jeep/boat the DUKW, and bigger heavy freight trucks for military use that migrated considerably to civilian long-haul and mining trucking technology. Trucking matters a lot more than cheap submachine guns in all kinds of things, payload, roads required, service life, maintenance cycle, fuel use...all very big deals worldwide.
I know surgery, especially trauma/emergency surgery, physical/occupational therapy, prosthetics, blood plasma and transfusion technologies, pain and burn treatment, plastic and reconstructive surgery all made advances that might well have taken 50+ years of peacetime medical research to achieve. So hundreds of thousands of lives saved or functionality restored is a big impact over time.
Quonset huts, the metal strips used to create instant airfield runways in the Pacific campaign, the artificial ports and port facilities, landing craft, amphibious assault equipment, Mae West inflatable life jackets, a lot of combat engineering technology like much improved pontoon bridging, maybe plastic explosives? Napalm, thermite bombs, magnesium flares, other bomb technologies and fusing/controls.