Solid-state CODEX NMR experiments directly probe chain dynamics in pure polyisobutylene (PIB), head-to-head polypropylene (hhPP), and their binary blend. The conclusions we draw from the results of the CODEX experiments, which are conducted over a temperature range of 210-300 K and which probe frequencies of 5 - 10 Hz, indicate that the overall chain dynamics of the blend system exceeds that of the two unmixed polymers. This is in agreement with our previous work on miscible PIB/polyethylene-co-butene blends [Macromolecules 2003, 36, 4844-4850], in which configurational entropy was shown to increase for miscible polyolefins. The CODEX experiments on PIB/hhPP, which offer the advantage of direct and simultaneous observation of both chains in the blend, show that conformational reorientation in hhPP increases significantly upon blending with PIB, while PIB chain dynamics are relatively unchanged. Rotating frame spin-lattice relaxation experiments support this conclusion. The benefits of direct chain observation of both polymer blend components at mechanically relevant frequencies (hertz) are compounded by the lack of any isotopic labeling requirements. These results on PIB/hhPP further support an entropically driven miscibility as a general phenomenon in nonpolar polyolefins.