I can't tell you not to purchase those fabricated valve covers but WILL tell you that several sets have arrived here the last few years; all but one set had to be returned because light showed through the welds. The factory "polishing" job also leaves much to be desired from what I've seen, as the bolt recesses and gasket rail are essentially ignored by whomever does the buffing.
The valve covers will oxidize and tarnish over time if they aren't protected somehow. Most like the Zoop Seal products mentioned before work great but they don't last forever and will require occasional polishing touch ups.
The intake will be a lot more difficult to keep clean. Fuel leaks combined with engine heat will be the biggest culprit that will affect not only any current polishing job that it has now, but aluminum is a very porous metal that will absorb fuel, carb cleaner, etc. too. It's what makes used intakes look grungy, splotchy and uneven. You can blast it all clean but unless you protect it in some way it will happen all over again eventually.
I'm happy to help you choose a path. Just give me a call and we can go over your options.
