1988 Roller Rocker Conversion

[Truck]

I'm thinking of replacing the Stock Rocker Pedastals in my 5.8L (351W) for fuel economy. What else would I need to accomplish this-other than the Roller Rockers themselves? I understand I may need new pushrods, but would the stock ones suffice in a pinch? Do I have to replace the lifters, or the cam?

The fuel bill on this beast is monstrous. (I'm sure we all know.) And the price I can replace the rockers represents only a month or two of fuel. (Maybe weeks.)

I have been in the valvetrain when I replaced the head gaskets..so I've seen all the components, but I'm not at all knowledgeable about how the Roller Rockers effect the valvetrain. HELP?