1968 Chrysler Newport Custom Tire Size
 

The tire size I found was 195 75 14 as the original size. Wanted to know if I found the correct information before buying.

i have a 1967 chrysler paper service manual. for Newpoirt
Wheel size
1. standard,,,,,,,,,,,,14 X 5-1/4
2. station wagon......15 X 6K
3. disc brakes..........15 X 6k
minimum tire size , sedan,,,hardtop...convertible
full rated load. 1100 lbs
1, standard............8.25-14
2. air conditioned..............8.55-14
3. trailer towing................8.55-14

I would expect a Chrysler to have 15" wheels
205/75R15

The original would have been something like f 78 14 I don't know what that would convert into in a metric tire. If you have to stay with the 14's get the biggest tire that will safely fit your rims. Plenty of room under there.
They were 14" from the factory unless otherwise specified, such as mentioned above. Towing, disc brakes, all special order.
I myself wouldn't hesitate to go with the 15"ers if for no other reason availability.
Actually I have been hearing that the 15"ers are getting scarce too. A 16 inch rim could be nice if you went with the right wheels.
You can get some pretty big tires in those wheel wells. I always ran
235-75-15. That's roughly a 29 inch tall tire with a 9 inch foot print.

only if it had factory disc brakes