Newbie Needs Help with Backspacing on 17x9.5 Wheels for 71 Challenger.

[Challenger1971]

Hello!!

Im New to the forum and have a questions about tire size and backspacing. Im 21 and I am currently working on a 71 Challenger for my younger brother (17). Hoping to get it painted and drivable for his Senior Prom.   
It has a 383/auto. 8 3/4 rear end (56.5").

-I did use the search and tried to find my answer but no luck. I might of missed it.

Ok so I managed to get a good deal on some Eagle Alloy Rims Front: 17x8 Offset: +2 (4.58 BS) AND Back: 17x9.5 Offset: +8 (5.56 BS).
I bought them not doing enough research before hand but Im wondering if they will work on the 71 challenger.

Also I would like to run the BFgoodrich G-force KDW Tires but they don't have many sizes for 17" rims.

From my research Im almost sure the fronts will work. But what are the biggest tires size I can run in the Front. Possibly a 245/45-17? Please Chime in.

For the back I have no clue. I think the back spacing is too much but Im not sure. Would like to run at least a 275 Tire but if I can go bigger that would be nice.

Also I heard that if my backspacing is too much in the back. I can swap a B-body 8 3/4 rear end. I heard they bolt right up but not sure. Does anyone know the year I can use out of a B-body???

Please chime in on the tire sizes I could run in the front and in the back.

Also I have started to save up as well as my brother to get the Hotchkis TVS System for the Challenger I believe the kit lowers the car a little but Im not positive. So if anyone knows if it lowers the car or how much it lowers it. I wouldn't want to run the biggest tire size due to rubbing issues.

Me and my brother both like the look of a challenger just a tad lowered with the wheels tucked in just a little if possible.

Dont know a lot about mopars but we are learning. 

Thanks in advance to everyone who gives me some advice and knowledge.

[bigblue73]

Here is what I run and I have plenty of room.  I run 17 x 8 front with 4.5" back space (0 offset) and 245/45/17 Nitto 555's and 17 x 9 rears with 5" back space (0 offset) and 285/40/17 Nitto 555's.  The 285's have a slight bulge to them which I prefer for rim protection. 

Measure from the face of the drum or mounting face of your rear disk break in towards the leaf spring to see what clearance you will have.  Remember the back space is to the outside of the rim from the centerline and NOT to the bead.  You may be close with the 5.56 inches of backspacing.  Measure twice my friend!

[cudazappa]

on the front:
17x8s and 245/45s will be very happy.  Its about as wide as you want to go in front.  The real enemy in front is tire height.  The 245/45 is about 25.7" tall.  At that height you could run a 275/40, but your rim is "in general" too narrow for that.

in the rear:
I run 17x9s with 275/40s in the back with 0 offset.  no probs.  your 9.5" wide with +8 offset is essentially adding 1/2" towards the spring.  my rims have about 1" in between them.  Yours would be about 1/2"   (attached picture)  Depending on the Brand of tire, that could be a problem.  A thin spacer of no more than 1/4" could help out.

Going to a B-body rear end would not help with this.  The b-body rear is narrower and would make the rims closer to the stock springs.  A popular thing is to move the springs inboard about 3/4" (would have to re-weld the perches on the rear end)

[Challenger1971]

Hey bigblue73 and cudazappa!

Thanks for replying guys! Yup I took the advice and measured. The rear rims I think will work but just to be safe Im going to go with a 1/4 spacer to move it off the leaf springs a little.

I attached pictures so you guys can see what Im working with. I will be ordering tires soon.

[Challenger1971]

More Pictures Sorry for how small the images are.

[bigblue73]

No problem running a 275 side tire with no spacer.  Remember the side walls are almost vertical with the outer edge of the wheel lip.  Go for it.