WILL F70 RED LINES FIT STOCK 67 BARRACUDA?

Yes I think they will fit on the factory 5.5 rims. Fs were 7.75 treads, and so translate to about 9.25 section. They want 8" rims but you cannot put 14x8s on the front, at a backspace that won't at some point in the suspension travel/steering angle, either, put the inside sidewall into the strutrod or frame, or the outside one, into the fender; so you can't use a 14x 8 at all. You can use a 7, but it will pinch the beads in and the tire will not sit flat on the road at normal pressure; and so the outside two ribs will wear at a much slower rate than the centers. You can solve this by running a very low tire pressure, perhaps 24psi, but at that pressure, the car will handle very poorly.
If you try to run Fs on the 5.5 rims;
I mean you can put them on there but 5.5s are designed for E's max. What I mean is the factory put Es on 5.5s, but really, the equivalent to an E (7.35 tread) in P-metric is about a 175 section. Anyway, you can put an F on a 5.5, but you will not get decent handling on it, nor decent treadlife .
If you're just tip-toeing around,you might think that would be fine, but you have to also keep in mind that your front wheels and tires also have to handle about 85% of the brake load, so you really want the tires to be flat on the road at a decent tire-pressure.
To illustrate;
I also have a 2nd gen Barracuda(68) and:
on the front are 235/60-14s on 7.5" rims which spec out as 9.25 section when installed on a 6.5 rim. On my 7.5s that would be at least an inch more; so 10.25 section. The height is about 25 before being bolted on. I have to run these at 28psi to get even-across-the-tread wear.
On the back I have installed, into the stock tubs, as much as 325/50-15s on 10s which IIRC were ~13.8 section and close to 28 tall before being bolted on. To do that, I only had to move the springs and run a custom backspace.
After that, I narrowed the rear end so I could run off-the-shelf 4.5 backspace wheels, so now, I run 295/50-15s on 10" rims, at 24psi.

But as said; Polyglass was cutting edge in 1970, but the reputation of Polyglass is legendary. If you have a slanty and never drive over 30mph, you'd be ok.
On a 340 Swinger, those factory supplied E70-14s turned that car into the most evil handling POS-car a 17 year old kid could ever have. I learned to drive in one of those 340Swingers and I can attest to that it was like driving on ball-bearings all the time. I give all the credit of my driving prowess,lol, directly to those tires. I had several hi-school nicknames; like Ditcher, Ditch-hitter, and 360, and Circle Clown or something. It took me all of summer of 71 to master that plick, and then the tires were wore out.
I was so thankful when radials came out.
But gosh those raised white letters looked so nice all cleaned up and fresh-painted...
I got three pieces of advice; 1) never buy a cam for the rumble, and 2) never buy a Polyglass tire, and 3) never marry a divorced woman, while her ex still lives.