Max Tire Size for '69 Mach 1 428 R CJ

[69428RCJ 3]

I am new to this forum so please forgive me.  I have researched this question on the internet and still unsure of the answer.

I just purchased a '69 Mach 1 428 R code CJ...numbers matching car for a lot of $$ and unwilling to roll the fenders, etc.

The car has come with stock steel wheels, , what I believe to be period correct tires, which are worth a good buck.

With that said. I'd like to replace these wheels with Magnum 500's...15X7 in front and 15x8 in the rear.  I'd like to know, without making any further modifications to the car. what is the largest size tire I can go with in the front and rear.  Now...I have a '16 Shelby GT 350 with 305s in the rear...I know I cannot come close to that size but would like a 275 in the rear if possible?

I would appreciate any and all feedback.

TY

Michael  

[RPM 1,256]

Hey Mike, welcome to the forum. I rolled my fender lips so I can't help you, but someone who can will be along with your answer. 

In the meantime we're a friendly bunch here, and enjoy looking at pics of members cars. A short bio about you and your car, and where abouts your from would be appreciated. 

Bob

[Mach1 Driver 602]

Hi 69428RCJ, We have a member who has been absent for some time now, but per barnett468 who has restored 50+ of these cars, the largest wheel in front for a 69 is a 15x7 with a 4.25 back space, while the widest tire that won't hit under some conditions is a P235/60R15. There are multiple members that run this wheel/tire combination, and this will also work with the Arning drop. Barnett recommended Specialty Wheels.

[69428RCJ 3]

Thank you Gents.

A bit about myself.  I am from Detroit originally and have been a Mustang nut since the age of 9...I'm 55 :).  I had a 68 coupe many years ago but sold it.  Now that my boys have graduated college and off the payroll so to speak, I felt it was time to acquire my dream car, a '69 Mach 1 428 R 4 spd.  Well that's not totally true, my true dream car is a '69 Boss 429 but that is not in the cards at the moment.  I now live about 35 miles outside NYC.  I have attached a few pics on my baby.

 

TY for the welcome.

Michael  

[69428RCJ 3]

Thank you Gents.

A bit about myself.  I am from Detroit originally and have been a Mustang nut since the age of 9...I'm 55 :).  I had a 68 coupe many years ago but sold it.  Now that my boys have graduated college and off the payroll so to speak, I felt it was time to acquire my dream car, a '69 Mach 1 428 R 4 spd.  Well that's not totally true, my true dream car is a '69 Boss 429 but that is not in the cards at the moment.  I now live about 35 miles outside NYC.  I have attached a few pics on my baby.

The gent in  the pic is my cuz, he has a '71 Boss 351.  I purchased the car in Michigan.

TY for the welcome.

Michael  

[RogerC 150]

Can't help you with your question but welcome to the forums. Black Jade?

[det0326 194]

Welcome to the forum, lot of guys with a lot of experience here, that are willing to help anyone. Very Very nice car I can see why don't won't to roll the fender and quarter lips. No help with tire size but a lot of guys on here will be. Good luck with the upgrade

[Mike65 509]

Welcome 69428RCJ, nice looking 69 Mach-1. There is a thread that someone was asking about tire sizes on a 69, here is the link. Whereabouts in NY state? My wife & I used to live in northern NJ.

69 mach1 Wheel and tire size - 1969-70 Technical Forum - 69stang.com and 1969stang.com The 1969 and 1970 Mustang Supersite

[RPM 1,256]

Ya, I'd keep that R Code stock too, she's a beaut. Is that your red GTO in the background Michael?

 

[69428RCJ 3]

TY gents!

I live in Rockland County NY (Nyack) ...right over the border from Northern NJ

No that is not my GTO, the gent I purchased this car from had:

• 2 - 67 GTO's factory 4sp cars...one with tri power!
• 1 Thunderbolt - 427 dual quads, acid dipped doors, fiberglass hood, etc
• 70 Mach 1 428 R 4sp
• 2014 Shelby GT 500

And those are the ones we saw...crazy!

Yes it is Jade Black

Really appreciate the support.

 

[TexasEd 202]

23 hours ago, 69428RCJ said:

I am new to this forum so please forgive me.  I have researched this question on the internet and still unsure of the answer.

I just purchased a '69 Mach 1 428 R code CJ...numbers matching car for a lot of $$ and unwilling to roll the fenders, etc.

The car has come with stock steel wheels, , what I believe to be period correct tires, which are worth a good buck.

With that said. I'd like to replace these wheels with Magnum 500's...15X7 in front and 15x8 in the rear.  I'd like to know, without making any further modifications to the car. what is the largest size tire I can go with in the front and rear.  Now...I have a '16 Shelby GT 350 with 305s in the rear...I know I cannot come close to that size but would like a 275 in the rear if possible?

I would appreciate any and all feedback.

TY

Michael  

I have the Magnum 500s on my car.  This is the size and the look.

Coker Magnum 500 15x7 front, 15x8 rear

Cooper Cobra P235/60 R15 in front, P245/60 R15 in rear

Suspension Mods Sourced from Opentrackerracing :

1" UCA drop, 560 1" drop coil springs, 1/4" Poly coil spring insulators, 1 1/8" front sway bar kit, Roller spring perches, Standard Upper arms, Standard Lower arms, New Strut rod bushings, KYB Front shocks, Grab-A-Track rear shocks, 4.5 Mid eye 1" drop leaf springs with new U-Bolt, front eye bolt and rear shackle kit

[WEEKEND CRUISER 18]

On 12/19/2023 at 7:47 PM, 69428RCJ said:

I am new to this forum so please forgive me.  I have researched this question on the internet and still unsure of the answer.

I just purchased a '69 Mach 1 428 R code CJ...numbers matching car for a lot of $$ and unwilling to roll the fenders, etc.

The car has come with stock steel wheels, , what I believe to be period correct tires, which are worth a good buck.

With that said. I'd like to replace these wheels with Magnum 500's...15X7 in front and 15x8 in the rear.  I'd like to know, without making any further modifications to the car. what is the largest size tire I can go with in the front and rear.  Now...I have a '16 Shelby GT 350 with 305s in the rear...I know I cannot come close to that size but would like a 275 in the rear if possible?

I would appreciate any and all feedback.

TY

Michael  

 

I'm running a 15x8 Magnum wheel with 4.5" backspace. My tire is a Mickey Thompson ET Street radial tire size 275/60/15. And the rear has been lowered a inch from factory height. No modifications have been done to my car to make the rear tires to fit. Below is a picture of my car, hope this helps.

[WEEKEND CRUISER 18]

Also forgot to mention my car is a 428 Cobra Jet car "Q" code. My front wheel is a 15x7 and backspace is 4.25", front tire size is 235/60/15. No modifications to the front or back with the tires, and no interference.

[69428RCJ 3]

TY gents...really appreciate the input

[69428RCJ 3]

After giving this some thought, I think I am going to stay with the original style wheel but go with 15 x 7 up front and 15 x 8 in the rear.  The main reason I bought this car was due to the fact that it's pretty close to original form.  If I put Magnum's on it (which I love BTW), then I would be straying away from originality.

I like to go with the following set up:

• Front - 15 x 7 - 225 or 235s
• Rear - 15 x 8 - 245s or 265s 

What I still do not understand is if a 265 will fit in the rear in stock form

 

ML

[Mike65 509]

69428RCJ, I like the wheels that are on your Mach-1, I have the GT version on my 69 Coupe that I had from a 68 GT Coupe that I had back in the 80's. Yours look to be chrome, mine are silver painted.

 

[det0326 194]

16 hours ago, TexasEd said:

I have the Magnum 500s on my car.  This is the size and the look.

Texas Ed u have your car looking absolutely beautiful

[TexasEd 202]

6 hours ago, det0326 said:

Texas Ed u have your car looking absolutely beautiful

Thanks but that was before I stripped it down.  It is in primer now.  There is a link to my build thread on this site.  https://1969stang.com/forum/index.php?/topic/47301-69-fastback-first-car-in-1985-bought-it-back-in-2011/#comments

 

It had badly peeling paint and then it rolled into a tree so now it looks like this:

 

[aslanefe 348]

10 hours ago, 69428RCJ said:

 

What I still do not understand is if a 265 will fit in the rear in stock form

 

ML

Looks like you missed what WEEKEND CRUISER posted above. He said  "I'm running a 15x8 Magnum wheel with 4.5" backspace. My tire is a Mickey Thompson ET Street radial tire size 275/60/15. And the rear has been lowered a inch from factory height. No modifications have been done to my car to make the rear tires to fit. Below is a picture of my car, hope this helps."

If 275/60/15 fit in the rear with no mods, 265 will sure fit with no mods if you use a wheel with 4.5" backspacing.

[69428RCJ 3]

TY sir

[Mach1 Driver 602]

On 12/21/2023 at 5:34 PM, TexasEd said:

Thanks but that was before I stripped it down.  It is in primer now.  There is a link to my build thread on this site.  https://1969stang.com/forum/index.php?/topic/47301-69-fastback-first-car-in-1985-bought-it-back-in-2011/#comments

It had badly peeling paint and then it rolled into a tree so now it looks like this:

Ed, that "before shot" is just stunning and I'm sure you'll get her looking even better.  I appreciate your detailed description of the suspension, but I think there is still one thing left out; you have KYB Front shocks, and Grab-A-Track rear shocks, but are they gas shocks or hydraulic? As you probably know, gas shocks expand and actually lift the car some and change the spring rate, while hydraulics don't, and hydraulics are actually what our cars were designed for. So which do you have? I'm not trying to spark a debate about gas/hydraulic, I'd just like to know what contributed to the look of your car, cause that is just about perfect.

I haven't decided if I want bigger tires in the rear or not. The smaller front tires sometimes look a little undersize when in the rear, but Weekend Cruiser's Mickey's look a little oversize. Maybe that's just because I prefer raised white letters and they look a little bear without them to my eye, but both are very good looking cars.

[TexasEd 202]

Not gas shocks. I got everything from OpenTracker several years ago. It’s what he recommended for me at that time. 
 

https://opentrackerracing.com/

[det0326 194]

On 12/20/2023 at 11:51 PM, WEEKEND CRUISER said:

I'm running a 15x8 Magnum wheel with 4.5" backspace. My tire is a Mickey Thompson ET Street radial tire size 275/60/15. And the rear has been lowered a inch from factory height. No modifications have been done to my car to make the rear tires to fit. Below is a picture of my car, hope this helps.

Nice car Weekend Cruiser, noticed you are in western NC. I am in SC and I have a Mustang enthusiast thats a friend of mine in Murphy NC. Wounding how close you are to him.  

[Mach1 Driver 602]

On 12/23/2023 at 10:42 AM, TexasEd said:

Not gas shocks. I got everything from OpenTracker several years ago. It’s what he recommended for me at that time. 
 

https://opentrackerracing.com/

Thanks Ed

[san408 18]

On 12/20/2023 at 10:51 PM, WEEKEND CRUISER said:

 

I'm running a 15x8 Magnum wheel with 4.5" backspace. My tire is a Mickey Thompson ET Street radial tire size 275/60/15. And the rear has been lowered a inch from factory height. No modifications have been done to my car to make the rear tires to fit. Below is a picture of my car, hope this helps.

 

I'm running the same tire on the rear, but with a 10" wheel that has a 5.5" backspace.  The rear is factory at the moment, but the lip is rolled.  I figured I'd just show for comparison purposes.  My last set of wheels were 15x8" Centerlines, and I also ran a 275/60/15 tire on them lowered with a 1" block. You can see that the drag radials are also a little taller than the old Goodyears I had on the Centerlines.