The objective is to determine how surface texture and conditioning protocols affect bond strength and reliability between cobalt–chromium (Co–Cr) post-and-core restorations and cast metal crowns, and to derive a texture-specific clinical algorithm. We tested 45 bonded joints in a 3 × 3 factorial design (Texture: polished, fine-ground, coarse-ground × Treatment: none, sandblasting, sandblasting + 10-MDP), n = 5 joints per cell (45 posts and 45 crowns manufactured) were cemented with a dual-cure resin cement and tested on a universal testing machine using a tensile, shear-dominated jig (Ø 8 mm × 6 mm; 2 mm/min; MTS Bionix). Two-way ANOVA with Tukey’s HSD evaluated effects and interactions; Weibull analysis assessed reliability. Treatment significantly increased bond stress (p < 0.001) with a texture × treatment interaction (p = 0.016). Sandblasting improved bonding across textures, with the largest gain on polished posts vs. control. On polished surfaces, primer improved bond versus control but did not add beyond sandblasting; an additional primer benefit was observed only on fine-ground posts. Coarse-ground posts showed no primer advantage. Weibull analysis identified the polished-sandblasted condition as the most reliable (higher m/σ₀). Sandblasting is broadly effective; primer use should be texture-dependent. Optimal protocols are: polished—sandblast only; fine-ground—sandblast + 10-MDP; coarse-ground—sandblast only. A simple, texture-specific protocol can improve both mean bond stress and predictability for metal-to-metal luting in prosthodontic workflows.