Welch Plug

So I bought a freeze plug kit from Summit for my 360 that's getting built and I realized that the welch plug (The dish shaped one, at the back of the camshaft) that came with the kit has gone awol. After 2 hours of tearing the garage apart looking for it, I have run out of options. The local places, (The Zone, Advance, Orielly's) keep trying to push a regular freeze plug on me claiming that is what I need, which is NOT. Despite the fact it's not expensive, I'd hate to buy a whole new set for one piece. Anybody got one laying aorund or good advice on where to get the one plug I need? Thanks!