255/60/15 - stock 70-72 Dart

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I just installed my 255/60/15 MTs under my 71 Swinger, i went with the 15x7" Rallyes with 4.25" BS, i'm glad i did because its tight enough, i don't think you'll get an 8" rim under there without modifying something, right now i have about 3/8" too 7/16" spring clearance from side to side, & alittle more on lip clearance, i've decided i'm going to trim the lips back some.
 
JoeDust451 said:
I just installed my 255/60/15 MTs under my 71 Swinger, i went with the 15x7" Rallyes with 4.25" BS, i'm glad i did because its tight enough, i don't think you'll get an 8" rim under there without modifying something, right now i have about 3/8" too 7/16" spring clearance from side to side, & alittle more on lip clearance, i've decided i'm going to trim the lips back some.
Click to expand...

Can you post some pictures of your install??

I am going to pull the trigger next week on the wheels and tires, dont want to screw up!!

Thanks!
 
JoeDust451 said:
I just installed my 255/60/15 MTs under my 71 Swinger, i went with the 15x7" Rallyes with 4.25" BS, i'm glad i did because its tight enough, i don't think you'll get an 8" rim under there without modifying something, right now i have about 3/8" too 7/16" spring clearance from side to side, & alittle more on lip clearance, i've decided i'm going to trim the lips back some.
Click to expand...

Yes, pics please!
 
Make sure you get some good stiff bushes too. I put some energy suspensions poly's in and it stopped all the tire rub problems I had with my 245's.
 
Here you go, i'll take better close-ups when the weather warms, it was 15* out with 25 mph winds, thank god i was blocked by the building, ignore the missing lug lol, this was just a mock up, of coarse i couldn't resist testing out the Mickies, yeah, "they hook" even with the 1 legger.

Mad Dart, if you have everything stock on your dart, this is what you want.

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When you look at the last picture, it looks like theres more room then there really is, especially at the springs, i made sure this was the best way to go for fitment (from a member here) before i purchased, Thanks Doug 371 for your help 8)

If you don't mind the Rallyes wheels, i'm sure this set-up & tire size will handle even a BB & still hook well with some suspention mods.
 
Joe Dust,

Thanks a bunch. I appreciate it. Looks like that will work! Just want to make sure here that your back spacing is 4.25 on a 15x7 Correct?

Unless I get a wild hair and move the springs and do a mini tub...haaaaaaa

With moving everything it looks like a 12' tire would fit with a 10" Rim!

If I install the cage this might just be the turn that I take.
 
Cool, looks good!

Since I started this thread, I've been doing a little research into tire size/gearing. Seems like the best overall tire diameter with the 4.10 gear I have would be 26". For best performance with the 255 (27" diameter) I probably would need a 4.30 gear. I believe that 4.10 is probably the absolute limit for 'normal' street/highway driving which therefore negates the benefit of 255's. I may end up with 235/60/15 M/T's or 26 x 9 QuickTimes.

I also asked this because A) I didn't want the extra cost and labor involved with moving the srpings in and B) didn't want the expense of buying new rims to fit the application since I already have two sets of facotry 15 x 7 rims with the 4.25" backspace.

I do however like the look of the 255's. Descisions descisions.
 
rmchrgr said:
Cool, looks good!

Since I started this thread, I've been doing a little research into tire size/gearing. Seems like the best overall tire diameter with the 4.10 gear I have would be 26". For best performance with the 255 (27" diameter) I probably would need a 4.30 gear. I believe that 4.10 is probably the absolute limit for 'normal' street/highway driving which therefore negates the benefit of 255's. I may end up with 235/60/15 M/T's or 26 x 9 QuickTimes.

I also asked this because A) I didn't want the extra cost and labor involved with moving the srpings in and B) didn't want the expense of buying new rims to fit the application since I already have two sets of facotry 15 x 7 rims with the 4.25" backspace.

I do however like the look of the 255's. Descisions descisions.
Click to expand...

Hey, don't jump the gun yet on buying tires, i measured my 255/60/15s just for kicks, they were 26.1" tall, now this was not mounted, but the inner beads were sitting very close to 7", so i don't think the tire grew enough to make them 27" tall, but i'll double check them tomorrow, i'm running 20 lbs. air in them, so i'm sure they are squatting flatter or still around 26" tall, i remember when i bought a set of Hoosier DRs for my camaro, on the factory 7" rim they sat less then 26", but they rated them higher then 26".

Mad dart, they are 4.25" BS, don't sweat it, they will fit, but if you are thinking of moving the springs in, or even a minny tub, this won't be the route to go of coarse.

Thanks Doug.
 
Was going by the specs on the M/T website which says 27.1", never had a set in my hands to actually measure.Curious to hear what they measure when you get them mounted.
 
I measured again today, with air in them, i'm coming up with just shy of 27".

rmchrgr, why wouldn't you want to run a 27" with 4.10s? Are you looking for a certain RPM range, unless your shifting at 6500+, you should be just fine with 4.10s & a 27" tire i would think, if your making any power, you'll need tires under her, like some have told me, a 235/60/15 is just not enough tire for decent traction, & thats with a very mild 360.
 
IMO, 275's have no biz on a 7" rim. I have 255's on an 8" rim and look/fit perfect. My BS is 4.5"
 
JoeDust451 said:
I measured again today, with air in them, i'm coming up with just shy of 27".

rmchrgr, why wouldn't you want to run a 27" with 4.10s? Are you looking for a certain RPM range, unless your shifting at 6500+, you should be just fine with 4.10s & a 27" tire i would think, if your making any power, you'll need tires under her, like some have told me, a 235/60/15 is just not enough tire for decent traction, & thats with a very mild 360.
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Was just using some of the online calculators for optimum tire/gearing. It looked like I'd need more gear for a certain RPM. I put in 5,800 as my redline for a stock bottom end 318 running at 105 mph and it came up with 25.97". If I'm anywhere up over that mph, I need more tire or gear. It's not exact science though. Not sure what effect a taller tire has on ET with less-than-optimal gearing, probably negligible until you start going faster than 12's. I'd imagine that the slightly larger contact area would definitely help!
 
Hey JoeDust451, what rear brakes are you using?

I have LBP Moser axles and a stock-length A-body 8 3/4 housing. As I understand it, the 11" brakes everyone uses with the LBP push everything out, further decreasing the little room you already have.
 
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