This post is directed towards Viper Specialty, as I know his company does this conversion, but anyone else can chime in also if they have info. What exactly is involved in putting Gen 4 heads on a Gen 3? I know they won't just bolt on, and have different exhaust ports. Is it worth it to do this aside from the superior looks of the Gen 4 top? What would be the approximate cost to have this done? I know you can run a Gen 5 manifold if you have Gen 4 heads, so that would likely be what I go with if I decide to do this.