I would have to talk to the person that built it and find out what exactly has been done prior to going any further. The extra hole that's been drilled in the c/shaft counterweight doesn't appear deburred, so what's the overall work quality of the shortblock build and the balancing. One small visual opens up lots of questions. The new parts look...new, nice. IMO, nice cam also. On the used parts, I would clean and inspect the rockers, buy new lifters, pushrods, headbolts, other fasteners, timing chain tensioner, neutral balance damper (if the assembly is indeed neutral-internally balanced), correct springs to match cam, correct retainers and locks, hire someone with a good reputation to build the new heads. And yes, everybody has differing opinions on some of those items, but that's me. Good luck, let us know what you find out.
