[Christ]

It won't hurt low-RPM flow too much, but it will bother enough to potentially cause detonation at higher RPM/loads.

You're right about power, though. You'll likely have enough torque to keep longer gears and not have too much trouble on the low-end. Keep in mind that with propane, you'll likely lose some of your power. You'll also need to switch the ECU off so that it doesn't go nuts when you turn on the propane, so you'll need to figure out your ignition system as well.