Low molecular weight glutenin subunits (LMW-GSs) in wheat are critical functional proteins that regulate the processing quality of flour-based products. This study utilized two sets of near-isogenic lines (NILs) derived from the wheat cultivars Zhoumai 22 and Zhoumai 23 to investigate the effects of allelic variations at the Glu-A3 locus—specifically Glu-A3a, Glu-A3b, Glu-A3c, Glu-A3d, Glu-A3e, Glu-A3f, and Glu-A3g—on protein content, gluten properties, dough farinograph properties, cooking properties of fresh wet noodles (FWNs), and textural properties of FWNs and frozen cooked noodles (FZNs). The results demonstrated that Glu-A3f exhibited superior grain protein content. Glu-A3e negatively impacted the gluten index, and Glu-A3g showed favorable dry gluten content. Glu-A3b displayed enhanced dough mixing tolerance. Importantly, Glu-A3b was associated with improved hardness in FWNs, while Glu-A3g contributed to higher hardness and chewiness in FZNs. These findings provide critical insights for breeding elite wheat cultivars tailored for noodle production and optimizing specialty flour development.