You really need to mention whether you have a USA amp or a Korean amp.
8-32 x 1/2 is the specification, but it isn't necessarily the right answer.
I just went through this when restoring a pair of SVT-2 Pro, one USA-made and one Korea-made. The USA amp had feet, the Korean amp didn't. I bought a set of OEM bumpers from Mackie and bought the machine screws locally. The foot screw spec is 8-32 x 1/2 for both amps, but when I bought the 8-32 x 1/2 machine screws at the local TrueValue, they fit one amp and not the other. More specifically, the OEM feet/screws from the USA model would fit both amps, but the 8-32 screws I bought would fit the USA amp but not the Korean amp. I have a sneaking suspicion that the USA amp uses 8-32 screws and the Korean amp uses something close that's metric and ever so slightly smaller, like maybe M6? Either that or the 8-32 screws that I bought were ever so slightly out of spec on the large size, but I doubt that, because the Korean/American amps also have fitment issues with the screws that hold the top/bottom panels in place. You can swap them one way but not the other or you'll end up chasing new threads.
So I guess the real answer is that 8-32 is a starting point, but don't be surprised if 8-32 doesn't fit a Korean amp. It could be metric.