I had a new high pressure pump from a well known company, it came without top cover if the same one, I fitted it but it locked up when I tried to get pressure, the so called well known cosworth specialist treated me very badly, I removed my sump and just fitted a genuine cosworth pump and had no problems with that, If the same one as mine hope all will be ok, they just gave me duff info when I tried to get any advice from them, first they told me they had a report from the manufacturer stating my drive had caused the failure then a few weeks later told me they didn't know who the manufacturer was, you may be lucky, but from what I understand they are just standard pinto pumps with an uprated spring whereas a new genuine pump has had a few improvements done to it so is a better pump. If it works ok just leave as is as mine failed before I had even run my engine, so yours should be ok, I have given up trying to get a refund for mine as the costs to get anything will be more than the pump but I would never use them again and will have a word with them at the next show I see them at, good luck with your new engine