Wheel and tire maximum limits

[Pakrat 1,043]

Hey guys, during the process of changing over to a new laptop and cleaning out my files I came across this old wheel and tire chart, I know there are a variety of others out there too which maybe some of you can help use as a cross reference. OK so part one is back space. I plan to use a 17x8 rim up front and a 17x9.5 out back which is exactly what Boss429 has and when I asked what his back space was his answer is exactly what is listed here: 4.5 and 5.5" respectively. So given this, wouldn't you think that I would be safe in ordering the rims with this backspace without having to wait to install my Mustang Steve brake kit first?

 

Next is tire size, according to the chart the parameters you should stay within are P235/45ZR17 to P245/45ZR17 on the front and P245/40ZR17 to P275/40ZR17 out back. However I have some hand notes also stored from a converstaion I think I had last year with BNickel and for the front he recommended a 255/40 (or45) 17 which is past the max on this list. Likewise for the rear he mentioned up to a 295/40R17 for a 9.5 rim or 275/40R17 if I kept a matching 8" out back. This matches the high end of the 9" max on the chart though.

 

So I guess my question is do you think the tire sizes on the chart are playing it safe or is B a mad man?

 

Also, what incriment of measure do they use for the Tread width and Aspect ratio? Is it actually in mm or just a random industry number?

[bnickel 10,004]

i'm just a madman, but you already knew that. the tire sizes are actually in mm, so a 295/40 would be 295 mm wide and the sidewall height would be 40% of that or 118 mm. i wasn't necessarily suggesting that you go that wide out out back i was just saying you can if you want. that red boss 302 in the badass cars from the net thread has a 315/35 rear tire so let your mind wander there. oh and that is with stock sheetmetal too, not even a mini-tub. i do still suggest using a 255/45 up front, i just don't think the 69's look right with the tiny sidewall up front.

 

as far as ordering the wheels i'd wait to buy at least the front's until you get the MS kit on. the back you can order any time you want since you've made up your mind to stay with the rear drums.

[351carlo 10]

That chart is certainly just a loose guideline. Check Dodgestangs.

 

Personally I like at LEAST a 275 out back. I run 275/55/14's on stock 70 magnums, and a 28x11.50x15 ET Drag on a 15x8 Prostar with 5.5bs and spacers.

 

I rub a little here and there, but that was with the old sagging springs and no rear sway.

 

GO BIG OR GO HOME! I'd suggest at least a big 245 up front. They look good.

[BAMF69 11]

I'm playing it safe since im going to tuck the wheels once i lower it. I have 18x9 in the back with a 255/40/18 tire and in front with a 225/45/17 tire on 17x8. The backspace in the rear is 6" but i have a 1" spacer so i can change it to 5". The fronts have a 6" backspace too but i'm using 1.25" spacers because i don't like a big lip up front. I got the wheels from a friend for cheap so i had no choice but to use spacers plus with more backspace i can play around with offsets using spacers. I don't recommend spacers on a daily driver because their not that safe. Pics will come soon.

[Pakrat 1,043]

Ok that's helpful thanks. I never realized the aspect ratio was in a percent, I guess that's why it has always eluded me.

 

So sound slike the best thing to do is try a few tire sizes on the rims once I get them and see what looks and works best. I am thinking that it might be a good idea to keep the overall diameter close to what my current set is so that I don't have to deal with changing out my speedo as well?

 

Anyone have a quick link to Dodgestangs chart? I thought I had it somewhere but I guess not.

 

maybe I will try to contact Edbert too and see if his backspace changed at all from prior with the Steve kit. I really hate the idea of the car just sitting on blocks for a month while I wait for them Or worse having to swap out the brakes again just to drive on my old rims for a while.

[bnickel 10,004]

to get you in the ballpark the stock tire diameter is right at 26". sorry i don't have the link either

[351carlo 10]

Sorry I thought I posted this up last time....

 

http://www.dodgestang.com/Tire%20Fitment%20Guide%2069-70.pdf

 

Also, if you are reading this and haven't sent in your information, please do so. Things like this are valuable for us vintage guys, there aren't a dozen books out there telling you what you can get away with.

 

Good Luck Pak.

[Pakrat 1,043]

Thanks Carlo!

 

So B that 26" is for say a 225/70R14 ?

[351carlo 10]

http://www.jeeptech.com/javaAps/conv.html

 

Type in the size up top in the format

 

2xx/xxRxx

 

I am 275/55R14 ... gives you an approximate size.

[bnickel 10,004]

Thanks Carlo!

 

So B that 26" is for say a 225/70R14 ?

 

yep. same size as the stock F70-14. also the same diameter of the 235/60-15 front and the 275/50-15 rear tires i have on my car.

[stangme 105]

Just to throw in my 2 cents. The Les Schwab tire dealer who I ordered my 17" magnum 500s with called and said they arrived today, so saturday he is going to mount a 275 on the 9.5" rears and a 245 on the front 8" rim. Then he's going to let me take them to the shop where my car is at and mont them to check clearances. I want a 295 in the back, but he doesn't have any in stock right now, but he said he would give me the measurements on the differences between the two so I can check how they will fit. I think I will have to roll my fenders but thats okay. Anyway, I will take pictures and post the clearances saturday night.

[bnickel 10,004]

that's great man, can't wait to see them mounted up

[Pakrat 1,043]

:pinch: Man, I just spent 30 mins typing up my conclusion and the fricken board timed out my log in and erased my post, what a fricken bummer, I am way too pissed to start retyping it all now! :angry: AARRRRRGHHH!

[stangme 105]

Well, looks like I'm going to stay with a 275/40 on the rear for now at least until I do something different with my rear leafs. As you can see in the first picture, I only have 1/2" clearance to the leafs now, and the 295's that I want are an extra 1/2" wider then these. I have to roll my inner fenders but I knew that anyway, but my outers will be fine for now. I was thinking about using a spacer to offset the rim but the tireshop said they had seen quite a few problems with spacers. They recommended a bolt on spacer, but they are $300 each and I don't want to spend that type of money just to get a little wider tire on there. The fronts cleared fine with the 4.5" backspace and are 245/40s. I didn't buy either of the tires on the rims, the tire shop was cool and mounted up a couple of tires so I could check fitment, I wish tires really did only cost $40. The last two pictures are with various weight on the rearend, one is one guy the next is two.

[bnickel 10,004]

looks pretty good although i would suggest going with the 275/45 instead of the 40 series. gives it a little more sidewall and the 69/70 cars really look better with a bit more sidewall.

[MDinDestin 14]

Well, looks like I'm going to stay with a 275/40 on the rear for now at least until I do something different with my rear leafs. As you can see in the first picture, I only have 1/2" clearance to the leafs now, and the 295's that I want are an extra 1/2" wider then these. I have to roll my inner fenders but I knew that anyway, but my outers will be fine for now. I was thinking about using a spacer to offset the rim but the tireshop said they had seen quite a few problems with spacers. They recommended a bolt on spacer, but they are $300 each and I don't want to spend that type of money just to get a little wider tire on there. The fronts cleared fine with the 4.5" backspace and are 245/40s. I didn't buy either of the tires on the rims, the tire shop was cool and mounted up a couple of tires so I could check fitment, I wish tires really did only cost $40. The last two pictures are with various weight on the rearend, one is one guy the next is two.

 

Great post, what's the backspacing on the rear?

[Pakrat 1,043]

Great post, what's the backspacing on the rear?

 

Yeah, I'd like to know also. Is it the standard 5.5"?

[stangme 105]

sorry guys, was gone for a couple of days, the backspacing on the rear is the standard 5.5", and 4.5" on the fronts, I have to do a little bodywork on the innerfender as I am just barely touching the lip, but alittle hammering and it will be solved. If you are still running your original rearend then you should have no problem at all with the 5.5 backspacing. I bought B's '78 versaille and if I remember correctly its about 3/4" smaller than my original.