what gasket

hi all i have a 86 e-250 with a 460 that leaks oil from valve covers,need to know what set would be best for it both are same price fellpro sets one rubber one cork, the valve covers are metal not aluminum if that matters,
and is there any bars like on chevy that would fit to make it even on valve cover,you know when tightening a bolt down it bends the cover down in that part resulting in oil leak,
i know i have had that problem with chevys before but any advice would be great thank you all.

Ask at the parts store for the metal clamps or try a chevy clamp and check if it will fit.
I prefer the rubber gasket but use what you feel comfortable with.

Do yourself a favor, and get the FEL-PRO PERMADRY gaskets. They're more expensive, but you'll only do the job ONE TIME.