The SVT heads already have the extrude hone process applied. The 98 to just the secondary intakes, and the 99 and 00 to the primary and secondary intakes. I guess you could to the exhausts though.
It sounds like what you are describing is "port matching". In port matching, you match the ports of the heads to the ports of the manifold (and between the upper and lower intake manifold as well). This is usually done by using the gaskets as a template. Lay the gasket in place, and scribe the head or mainfold at the opening of the gasket. Then with a dye grinder gently open the port to match the gasket. It would be wise to study the topic a bit before you try it.
