I got mine from the machine shop I use, these are the same ones they use themselves, they check EVERY one dimensionally and every other way, and warranty the engines they build/supply with the same pumps, been going 54 years so somethings right, they don't do mail order, just pm me if wanted.
They use their own engine dyno's and chassis dynos, I spoke to them about oil pressure and was told pretty much what I suspected on most 60 psi is more than enough.
tabetha