The 915 heads would have the same chamber shape but bigger valves/more power, good swap idea. The Long Ram intakes are valuable, price depends on completeness (allot) and condition. They aren't much good to anyone for big power, they make torque at low rpms and flatten out quickly and don't fit the engine bays of most cars (no A,B, or E-body cars) without serious hacking. The restoration guys and Street Rod guys (for the wierd looks) are the ones who usually end buying them.