Well I bit the bullet...
"Tested" it, went up and down the interstate to make sure there was no buffeting or anything untoward. At very least it isn't hurting. Unfortunately I don't have any better data acquisition at the moment other than the MkI eyeball and tach vs. MPH reading. So initial look showed we're inching closer to 2600 RPM @ 68 mph. Before I started all this 68 was just below 2800 rpm. Now we're just above 2600 rpm. The tale will be the fill up. Though need to look into a ELM adapter for the OBD. Has anyone tried the Torque app for Android? Sounds like a Scanguage for $20 (about the cost of the ELM adapter, the app is free).