MY tyre placard

[Cliff R]

Inside the drivers door on my 1982 MY touring wagon the tyre placard states the original tyre sizes were as follows:

For 4-1/2J or 5J rims the tyre is a 155SR13
For 4-1/2J or 5J rims the 2nd option for tyres is a 155R13C 6PR
With this 2nd option apparently it is not recommended to drive the car over 90k's ht for long periods of time.
My rims are the original 1982 Subaru alloys that are 5-J x 13 but I am going back to my 14" steel rims and would like to know the 14" equivalnet to keep the speedo right.
Anyway, what does the 155SR13 equate to in todays tyres. ie, 155/70/13 etc.