Unless you have done a lot of modifications, the 19# injectors will be of no benefit. A lot of work and expense with no improvement in performance. It is not an upgrade unless you need it. If you don't need it, it is a downgrade.
So unless you enjoy beating yourself up, don't do it until you have made extensive modifications. Things like hotter cams, ported heads, 3.0 conversion, much bigger intake and exhaust, headers, etc. And not just one or two of them, several of them.
