Does this 17"/18"setup seem like it will work?

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scott2683

scott2683

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I've read 17"/18" wheel and tire threads on here until I went crosseyed. I have a 72 duster, it has all stock suspension, KH front disc, 8.75 A body rear. I'm in the process of switching it over to BBP, and I want to go with a 17" wheel. For the front end, I'll be picking up a set of 74 duster spindles, and brakes. I'm also adding QA1 UCA's and a sway bar.

From my research this is what I'm thinking and tell me if you think I'm in the ballpark with fitment.

Front:
17x8
25mm offset
I thought about a 225/45 but I'm thinking a little taller and a little wider like a 245/45.

Rear:
18x9
0 offset
275/40

If I went with a 245/45 front and a 275/40 in the rear, that should give me the same size sidewall front and back. I feel like the 225, is just too thin. I would do 17's in the rear, but they don't have the correct offset to make it look staggered.
 
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Going BBP will widen your track front and rear if you use 73-up OEM front discs and off the shelf BBP rear axles and BBP drums of any width or diameter.

When you do the QA1 uppers (I have them) Be sure they clear the arm mounts, I have to grind a chamfer that hit the tube but would otherwise clear the factory arm.

@72bluNblu Has probably wrote about wheel fitment so many times he has a word document saved to copy paste from.
 
dano said:
Going BBP will widen your track front and rear if you use 73-up OEM front discs and off the shelf BBP rear axles and BBP drums of any width or diameter.

When you do the QA1 uppers (I have them) Be sure they clear the arm mounts, I have to grind a chamfer that hit the tube but would otherwise clear the factory arm.

@72bluNblu Has probably wrote about wheel fitment so many times he has a word document saved to copy paste from.
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Thanks for the response! @72bluNblu seems to be the community guru, but I hated to bother him on a topic that's been addressed so many time.
 
I don't like a 225 tire on a 8" rim. They always look too skinny to me. But that's just an opinion.

Nice thing about a 245/45-17 on the front and a 275/40-18 in the rear is they match a C5 Vette for tire size. Makes them a size that should be readily available for a long time, and relatively cheap to boot.

For what it's worth, I am running a 245/45R17 on the front of my Duster, but I have about 5mm more positive offset than you are talking about. Amounts to 3/16" of an inch. I rub the bolt in the rear of the wheel opening once in a while but could fix that with less caster or a button head bolts. So height wise it should work for you as well.

72bluNblu (last time I checked) runs a 275/35R18 on a rim with 35mm positive offset. That rim put's tire about an 1" further out than yours would, so even allowing for differences in brakes and such, you should be fine there.

The other issue in the front is the tie rod end. I am close on mine so with 5mm less offset you will probably be fine there.
 
DionR said:
I don't like a 225 tire on a 8" rim. They always look too skinny to me. But that's just an opinion.

Nice thing about a 245/45-17 on the front and a 275/40-18 in the rear is they match a C5 Vette for tire size. Makes them a size that should be readily available for a long time, and relatively cheap to boot.

For what it's worth, I am running a 245/45R17 on the front of my Duster, but I have about 5mm more positive offset than you are talking about. Amounts to 3/16" of an inch. I rub the bolt in the rear of the wheel opening once in a while but could fix that with less caster or a button head bolts. So height wise it should work for you as well.

72bluNblu (last time I checked) runs a 275/35R18 on a rim with 35mm positive offset. That rim put's tire about an 1" further out than yours would, so even allowing for differences in brakes and such, you should be fine there.

The other issue in the front is the tie rod end. I am close on mine so with 5mm less offset you will probably be fine there.
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Thanks for the input! I'm right there with you on the 245/45. I think that's really the best route to go. I'm thinking of running Nitto G2's. They make both sizes, and they seem pretty cheap.
 
In the rear, I am going to guess that you will be fairly close to the wheel lip on the outside and fine on the inside. But not certain as I can't remember the width of a BBP 8.75 right now so going off info I have saved from other people.

Specifically, one guy was running a 9" rim with 5" BS (should be zero offset) with an A-Body 8.75 (assuming BBP) and a 275 series tire. He said he had to bend the rear wheel lip a tad. Lot's of assumptions there, so not feeling as good as I would like with that info.
 
If I'm not mistaken BBP backing plates will widen the track some. I'm running an 8" wheel now with -6mm offset. (15x8 cragar). According to the calculator I'm using I'll have .75" less on the inside and .25" less on the outside. That doesn't take into account the BBP brakes. My last duster I was able to squeeze a 275/50r17 on a 9.5" wheel back there with no modifications, but I can't remember the offset of that wheel. I think it was 8mm with a backspace of 5.56
 
225's looks net with a 8" wide rim. 235 might be a compromise between the two.

A-body 8-3/4 with BBP OEM Drums and proper axles will be about 1/8" wider per side. I think OE BBP is ~2.5" brake offset and SBP is ~2-3/8". Add another 1/8" per side for BBP rear discs like Dr Diff sells.

Front will widen ~3/8" per side with OE BBP Discs.
 
dano said:
225's looks net with a 8" wide rim. 235 might be a compromise between the two.

A-body 8-3/4 with BBP OEM Drums and proper axles will be about 1/8" wider per side. I think OE BBP is ~2.5" brake offset and SBP is ~2-3/8". Add another 1/8" per side for BBP rear discs like Dr Diff sells.

Front will widen ~3/8" per side with OE BBP Discs.
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Thanks for the info! I think a 235 might be about right. I really just don't think I want to go with a 225
 
In the front a 245/45/17 will fit fine, the 17x8 with +25 offset is perfect. Backspace is right at 5.5” so it will be tight to the outer tie rod end but should clear. If you wanted you could probably run a 255/45/17 up front, that would be 26” tall though which is about the upper limit for height with a tire that wide. Might have to adjust the front lower corner of the fender a bit, depends on the car and the ride height.

A 275/40/18 on an 18x9 with 0 offset should work as well. It will be tight to the quarter lip, but if you’re not lowered it should be ok on most cars. I think a +6 would be about perfect for a 9” rim with a BBP 8 3/4 and the stock spring location, it would be tight to the springs but that can be adjusted with a small spacer if need be. The shorter sidewalls can run tighter to the springs, but if you end up too close to the quarters you have to cut stuff. Plus it gives you a little room if you do a rear disk kit later (they add like 3/16” usually), so you can go disks without buying new wheels.

I do run 275/35/18’s on the front of my Duster (now Demon) but they’re on 18x9’s with about +30 for offset. That’s a 6” backspace, which you need for 9’s and 275’s. But you need 18’s to do it, most 17” rims end up with tie rod end interference around 5.6” to 5.7” of backspace. Depends on the rim, some do better but I’d say any time you need to go past 5.7” for backspace on a 17” it’s not likely to clear the tie rod end.
 
72bluNblu said:
In the front a 245/45/17 will fit fine, the 17x8 with +25 offset is perfect. Backspace is right at 5.5” so it will be tight to the outer tie rod end but should clear. If you wanted you could probably run a 255/45/17 up front, that would be 26” tall though which is about the upper limit for height with a tire that wide. Might have to adjust the front lower corner of the fender a bit, depends on the car and the ride height.

A 275/40/18 on an 18x9 with 0 offset should work as well. It will be tight to the quarter lip, but if you’re not lowered it should be ok on most cars. I think a +6 would be about perfect for a 9” rim with a BBP 8 3/4 and the stock spring location, it would be tight to the springs but that can be adjusted with a small spacer if need be. The shorter sidewalls can run tighter to the springs, but if you end up too close to the quarters you have to cut stuff. Plus it gives you a little room if you do a rear disk kit later (they add like 3/16” usually), so you can go disks without buying new wheels.

I do run 275/35/18’s on the front of my Duster (now Demon) but they’re on 18x9’s with about +30 for offset. That’s a 6” backspace, which you need for 9’s and 275’s. But you need 18’s to do it, most 17” rims end up with tie rod end interference around 5.6” to 5.7” of backspace. Depends on the rim, some do better but I’d say any time you need to go past 5.7” for backspace on a 17” it’s not likely to clear the tie rod end.
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Thanks so much for the response! I definitely appreciate your knowledge. My car isn’t lowered but I don’t want tons of wheel gap either. I’m hoping it clears the fender. I can always trim a little if I have to but I hate to go that route. I have absolutely changed my mind from a 225 up front to a 245 I think.
Thanks again!
 
DionR said:
Sorry, forgot that detail. I will do better next time. :thumbsup:
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No big deal, I call it a Duster more than I call it a demon clone. I ran the same rims and tires with both style front fenders, although the Duster fenders are more restrictive at the rear corner of the wheel opening than the Dart fenders are so the taller tire thing can come into play more with the Duster fenders.
 
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