My original steel idle mix screws and springs are in bad shape, so I'll be using the new brass screws that came in the HP kit I'm using. Aside from the different material they're made of, is there any difference in the screws? I notice the springs on the new screws are shorter than the stock springs. I have not opened up the holes under them, so no need for shorter springs. Seems like they'll be loose when the screws are screwed out several times for adjustment. I'm thinking getting some stock length springs would be better to keep them tight. I usually reuse my original screws and springs if they're in good shape, but can't this time. Opinions?