If he died in the UK There are two things you could look for, a civil registration entry of death, which would narrow down to a district where possibly he would be buried, and an entry in the burial register if he had a religious ceremony for the funeral.
If he died in the US you need to look at the social security death index, which would again give you a location of death, however, with cremations it is of course not always the case that the remains are interred at all, whether at the crem or in a churchyard, sometimes the ashes are kept with the deceased's family.