Tire and wheel size on '70 Newport?

[Big Muscle]

Hi guys -

A couple of questions for you. I'm looking to upgrade the wheels on a 1970 Chrysler Newport to a set of 15" Magnum 500's with BFG TAs however I'm not sure of the backspacing I should order and or how wide I can go on both the front and rear. Any ideas? I'd like to put as much meat on there as possible.

 

[71ChargerSE]

Curious about this myself.

 

[Big Muscle]

Anyone? I would think a 295 would fit back there with no problem... this is my first C-body though, so honestly, I haven't got a clue.

 

[commando1]

OK.
Go grab your tapemeasure, go outside and get your dimensions of the wheelwell:

Let's go to work...
Stock backspacing is 4-1/2"
Knowing that, you now know this:

Then you have to do your homework.
Go here:
http://www.miata.net/garage/tirecalc.html
Then here:
http://www.1010tires.com/Tools/Wheel-Offset-Calculator


Everybody thinks it's easy...
It isn't if you don't want to screw up the geometry of your suspension.