I don't have specific measurement information - but ... for Ford to put those 8 x 17 inch rims on the same car (the Mustang) and try to maintain equalized clearances....I think they would have to have utilized the same amount of offset. Make sense? The "backspace" to the edge of the inside rim would be greater by 1/2 inch to maintain that position.

In order to mount the 7 x 16 rims with the tire centerline directly on the hub mounting face would require a 1-1/2 inch thick wheel adapter. That thickness corrects for the offset

Other considerations would be -

How close does the inside sidewall of the front tire come to the steering knuckle? I have used 1-3/4 inch adapters with my set-up to get the inside tire sidewall away from the upper ball joint. 

Are the bolt patterns the same? The Mustang part is 5 on 4-1/2 - what is yours?

Which tire are you going to use? Mine has a 225/50/16 on there so the section width (fat part of the sidewall) = 225 ÷ 25.4 = 8.86 inches. If you take the tire size (section width) you intend to run and divide by two - then add the clearance you want from the upper steering knuckle (this is for the fronts now) and compare that with what you've got on there now - you'll be getting somewhere. The position of the steering knuckle - depending on the spindle height (the Granada disc brake versions are different than my 56 by an inch for instance) may be lower than the maximum sidewall width location - in which you can ..... by careful measurement tuck the wheel in a bit closer.

The real fun on the Birds  - dunno about the sedans - is at the rear. The closest clearance inside turned out to be from the leaf spring to the sidewall - behind the axle (the springs are not mounted parallel - wider to rear). At the outside fender lip it was at the centerline of the axle (when I sat on the fender to collapse the spring a bit). So at the rear I used a 1-1/4 thick adapter - and could have used a 1 inch to pull it in a little more - but the 1 inch thick adapter looked spooky to me (not enough meat for the studs). 

I looked the tire wheel calculator - but it only had clearance specs for T-birds and trucks - no sedans. Guys have told me that if you want to have the same tire front and rear - even on the sedans - you are best to use 225's as the maximum and go from there. If you were to put the 225's on the 8 inch rims the section width would go out about .2 - to about 9 inches - pretty much even with the rims.