Restoration. . . "old school", or "newfangled"??

As many have said: it's really a matter of personal preference...

However, since you asked, I'm putting in my two cents! I had a 69 Mach 1 that I sold to my brother-in-law about 2 years ago (I don't have time to work on 2 cars, but at least I kept it in the family!) and my plan was very similar to what I did with my 67:

Restomod, but without making it look too modern. Start with the suspension: no need for coil-overs (unless you have buckets of money to spend), but definitely upgraded springs (custom cut to get it down in the weeds!), sway bars (the 69/70's need bigger bars than the earlier cars - rear bar is nice on the street, but I don't like them on the track), control arms (I was thinking TCP or GW tubulars), and strut rods (I love my Street or Track rods). I would also go to rollerized spring perches. For shocks, I'd go with the best I could afford as they can dramatically affect ride quality. Before doing any of this, I'd get some subframe connectors on it, so you're starting with a good foundation. Handling is the second most important thing for me (safety is number one).

Brakes - front wheel disc brakes (4 wheel discs aren't really necessary, even on most track cars, but look great). Wheels - 16 or 17 inch (personally, I love the Torque Thrust "D" look and you can now get that on the TT II's). Some wide, wide tires (275s would look good, but I'm not sure they'd fit in front).

I love the Shaker hood - looks nasty! Otherwise, a Mach 1 scoop (functional). Front and rear spoilers look good (at least I think so) and the front spoiler in particular does help keep the front end more stable at high speeds (which, of course, you would only see on the track - right?).

Roll bar and upgraded seats with full five-point harnesses (ProCar makes a seat that looks great in the vintage cars, but has great support for those high lateral G situations!).

Five speed transmission (what type would depend on how much power you end up putting under the hood).

Engine - I had a 351W and it was pretty strong (at least compared to my 67 and it's little 289). If I wanted more power, I would stroke the 351 or, for "Wow factor", go with a supercharger (big blocks make good handling much harder to achieve).

Paint is something I hadn't decided on, but I think the 69 and 70 cars look mean with anything from Primer on up! The one thing I do like is the semi-flat hood and accents (e.g, the front spoiler and scoop) - looks like business.

As you can tell, most of my changes would be functional, but not highly visible. I think these cars can definitely benefit from upgrades suspension, braking and engine parts, but they don't need much in terms of the body: they look great the way they are (or were).