engine noise?

[sdycke]

Hello. Just got a 91 with 13,000 miles but am not familiar with the LT5 at all. It has a slight engine noise that I wonder if I should be worried about . I know discussing noises in a forum is very difficult but who knows?. Its most noticeable cold and when you slightly crack the throttle. Then it pretty much goes away. It is a very faint, hollow knocking sound. Almost like a loose rod. I cant pinoint it whether its on one side or the other, but does sound more inside the engine. I may try shorting out plugs to see if that affects it. I understand these engines have some chain noise. I will be comparing it to a known good engine at the start of next week so that?s a start. I know these motors are bulletproof and the milage is low but I am finding many little things the previous owner ?forgot to mention?. Any seat-of-the-pants thoughts/diagnosis/opinions would be very welcome. Stan