I was totally thinking BTTF when I saw this thread...
googles thrust vector.... from what I'm reading, I believe you're asking about what MPH these cars are drag limited at? Correct? if so, somewhere around 145-150MPH without heavy modification.
Our front ends are huge air catchers! All the openings in the main grill, upper grill, bumper and hood stick out further than the grill. That is one of the reasons many of us experience "hood lift" above certain speeds. You would have to push the grill out to meet the bmper and hood and almost make it a solid piece so most air goes around it, not in it. So the retro S197 look is nearly on par with the front end aerodynamics of the Mustang IIs.
Perhaps he means thrust angle? The alignment angle? Also I don't recall and I'm at work at the moment so I don't have my service manual handy. I tried to google it but every promising link wants you to buy there spec book LoL
Hey, sorry guys, I meant thrust angle like towelly said lol. Does anyone know the factory specfied range for the thrust angle because I think mine might be too off center. I have a thurst angle of .12 degrees right now.