I have recently done a radiator on a 70's Brand F PU. Twice. First time was a parts store "extra cooling 3 core". I guess those 3 cores were not very thick and temp would creep up on a hard pull. Did it again with a 4 row Champion and works well (stock shroud fits in this application).

Point is, better/cheaper to get a good one first time. With no specs like tube diameter and core thickness I'd be a bit concerned about the LMC offering. I bet the re-core, if done with a high efficiency core, would be fine.