The data describes the trapped fields of the samples at different magnitisation conditions for the figures 3,4 and 6 in the paper. In this work, we investigate whether large, single grain samples are optimum for the generation of high levitation forces for engineering applications. Three large bar-shaped Y-Ba-Cu-O (YBCO) samples of dimensions 60 x 20 x 12 mm3 were prepared for this investigation, including one single-seeded, one multi-seeded and one consisting of three square samples packed together closely in an array. The processing of these samples is described and their trapped field and levitation performance at 77 K measured using different permanent magnet arrays. We find that the multi-seeded samples and those assembled from smaller, individual bulks are able to achieve a higher levitation force than an equivalent single seed sample arrangement, at least in some geometries.