"oh I also sanded off the powder-coating on the valve cover and its nice and shiny, I couldn't get myself to paint it some wild color"

Glad you fixed the leak, sounds like you had over torqued it initially.

Now about this sanding....
I went through this on my 103 and did end up painting the cover. I was told by many that on the 103 the cover is not 100% Aluminum - There is Magnesium there too. The valve cover material is porous and (without paint) is now exposed to the elements. In simple English - not good, needs to be painted.