@rene4406 posted:To increase the caster by 3 °, you have to move the upper ball joint back by about 13 mm (approximately because I don't have the courage to go to my garage to precisely measure the distance between the two ball joints), which will move the wheel * / - 6.5 mm in the wheel arch; I don't think that's really a big problem.
I read I don't remember where that the European Pantera had more roulette and that Ford asked that there be less on the US models because in the 1970s, unlike the Europeans, you Americans were already very accustomed to power steering, therefore light, on the one hand and were already subject to speed limits on motorways which made great stability at high speed unnecessary on the other hand.
The recentering doesn't sound like much but consider that the original tire size was a 185-78-15 and was mounted on a 7" wide rim.
Presuming that one stays with a 15" rim and 8" wide, you can mount a tire of 245-50-15. The entire nature of the clearance on the tires turning arc is altered.
Even so, that concerns me less then what exactly happens to the bump steer?
It is possible that there will be several here that will laugh and say, "Doug doesn't know what he is talking about. I have the +6° and I have NO bump steer".
Well I'd LIKE TO take that as an accurate statement but let me just make a point here. I have personal hands on experience with the '65 Shelby GT350.
That car had a suspension modification done post Ford, by Shelby. That modification introduced a nasty amount of violent bump steer to the car.
Was that even mentioned in magazine road tests of the time? Answer: rarely.
Did owner ever complain about it? Almost never.
So what's my point. Until sometime in the mid to late '70s, owners didn't even realize that there was an issue. They didn't know what the term bump steer even meant.
They thought that the tires were over inflated and/or the Koni shocks were set just to high on rebound?
Now I really don't INTEND to ruffle feathers and call current Pantera owners names inferring that they are stupid, but there are many GLARING examples in posts right here on this forum that would indicate to me that the general knowledge base amongst them is embarrassing low.
In fact, it makes me wonder how the vast lot even would up with these cars at all? Did you go out to buy a pickup truck and saw the rear decklid and thought you could carry hay back to the farm on it?
I don't get it?
I'm wonder how many here even would know WTF anyone is talking about when the subject of bump steer comes up? I'll bet they think it is some kind of a now obsolete "disco dance move"? 
Amazing! ABSOLUTELY AMAZING! LOL FOREVER!