Best tire pressure for 69 dart with P245 60R14

I would really appreciate if members that run larger tires like P245 60 R14 on stock suspension 69 darts and alike could tell what the best tire pressure would be for street driving as far as stability and even tire wearing.
I have a 1976 dart sedan assembled in Brazil, which pretty much is the same as a 69 US dart as far as body and suspension are concerned.
It came from factory with the old 7.35S14 diagonal tires. I currently have 205 70 R14 but they look skinny and I plan on buying a set of 7" wide 14" diameter 1970's magnesium rim wheels and put on a set of 4 P245 60 R14 hankook tires which are pretty expensive down here (about US$ 180.00 each). BF's are way more expensive.
Another question would be if these 245 tires would be good on the front too, I want to use them on all 4 wheels.
Thanks for your input on pros and cons.