Tire size for 74 Valiant Brougham

Hi All...thanks for responding.
I'm told that D78-14 or DR78-14 tires are original. When I shop, I see P185-75R14 or P-185-70R14s available as modern "closest" sizes.

FJR... you said P195-75R14 were on your Dart. I would think this is a more common size than the 185s. Only difference is that the 195s are a little under 1/2 an inch wider right? You have no issues with the tires rubbing on the rim? They work good for you?

Six 225..... are you running original rims on your car?

I see in all posts guys are using 75 aspect ratio. Anyone know what's the difference between the 70 and the 75s? Are the 75s preferred?