Brake line: 8.75 vs 8.25

Professor Fate said
Slow down, fella.
First off, if you've actually got an 8.75 in a '75 Dart Sport, it ain't factory. They had 8.25s.
So if you've got an 8.75, you've got to figure out which years it came from, pre '70 or post '70.
Why? Because they moved the vent and brake tee in '70. This affects the length of your brake lines. That means two different kits, and if either one is the same as that for an 8.25, who knows.
If your vent/tee is on the axle tube, it's the earlier version. If it's on the base of the center housing, it's the late version. Order the appropriate year lines for your rear end, NOT for the year of your car- that's why they're trying to sell you lines for an 8.25 rear.
Either order the right lines or bend 'em up and flare them yourself, it's not that hard.

Oh, I know it isn't factory, was just asking about lengths. The tee is on the tube, not the center housing, so that narrows it down.

I don't suppose there's a way to identify the original vehicle? I haven't seen any stamping on the tube itself, just on the third member, which doesn't necessarily say anything about the original car. Other than being a 741 case with 3.91 gears, that's the extent of the facts I have. :)

As for the flaring tool and bender, I considered it, but since I can get all new hard lines for about the price of investing in a tool which I'll use for one car, it's honestly hard to commit to that.