Starting to Panic a little...

[Luminox]

Well some background before I go into my possible problem. I have a 66 Mustang Coupe with a 289 basically stock. Drums all around but would like to do discs this winter so I can get through the projects I have on the table now. Ok here is my problem...

I recently ran into a guy selling a set of 17x8 4.25" BS Edelbrock 454s. They were brand new and never had a tire mounted so I grabbed them because the price and look was exactly what I wanted for my car. I was worried without reading anything that they would be tight but the guy assured me that if I ran 225/45/17 tires on them I shouldn't have a problem and since he owned a 65 I took his word on it. I've been reading every tire chart in the book and I found that I'm borderline if not over what I can logically put under the car...

My question is, What do I need to do to the car in order for me to be able to fit those wheels and tires under it. I'm not against doing the Disc Brakes as well but quite honestly I'd like to find the cheapest possible solution until I can afford them later.

Also I searched for tech info on rolling fendors and have come up with nothing that will truly help me so if you can point me in a direction that would be great. 300 dollars for the Eastwood Fendor Rolling tool is a bit much for something I would use once.

I send my car to the bodyshop for new Quarter Panels, Fendors, Doors, Front and Rear Valance, and Paint on July 24th so I'd like to have a plan for after it comes out or while it's in. If I have to roll the fendors maybe I can give the body guy a heads up and he can do that, he's charging me enough I think he would do that for me if I needed.

My homework for tonight is to measure the backspacing of the wheels to be exact and drop off 2 of the rims to my father for tires. I'm buying a set of 225/45/17 to test fit regardless, my father has sold tires for 30+ years so I get great prices so this is a inexpensive test as well.

Please if you can provide any help let me know,

Dominic

 

[dodgestang]

This image is a 235 45 17 tire on a 17x8 rim with 4.75bs on a 65 mustang

As you can see it is very close. It does not rub however and I did not roll the fender lip. But, if I were to try a 225 45 17 on a rim with .5 less backspacing, I know that it would not only rub but it would be most likely so far out past the fender, that simply rolling the fender would not fix the problem.

Things you can do to try and get it to fit:
1. Rolling the fender perfectly flat
2. Shelby mod and aggresive alignment: this will put a slight tip in to the top of the tire as opposed to the tip out stock mustangs have
3. Add a stiff, stock height suspension - ride quality will degrade, but it will help
4. Stay drum....every set of disc brakes I have seen add to the track width...some significantly (like the wilwoods) others only very marginally (almost imperceptable)
5. Add a small flare to the front and the back as part of the body work being done for painting (I have seen lotsa mustangs with small falres done that I think look very nice, and very aggresive) or have the shop bangout the sheetmetal as a little farther on the stock flaring of the parts (not the best idea but still workable)

 

[Luminox]

Ok, thanks for the quick response. Answer me a few more questions though. With playing around with measurements and wheel statistics if I drop to a 205/45/17 I lose 1.07 off the overall diameter of your 235/45/17 and 1.18 off the section width. I'd rather not go smaller than a 45 series sidewall if there is something else I can do to prevent that.

I was thinking about doing the Willwood brakes in the future too but it seems that would cause more issues that the price difference would be worth so I'll opt out of that idea for now. Do you happen to know the difference Willwoods would result in? I was thinking about a small flare but honestly this body guy is getting me for 5,000 now and I don't want my wife scowling at me any more than she is now. I will look it up though and talk it over with the bodyshop guy, hopefully we can come to a understanding since he's going to get a lot more business through me.

Thanks a ton for all the help,

Dominic

 

[dodgestang]

Will a 205 even fit on an 8 inch rim?

Wilwoods add between .75 and 1 inch IIRC....cloney would know for sure since he has them...I think he has an entry on the wheel chart for 65-6 just look for the 17s with the real funky backspacing and the wilwood brakes...he had to get them custom made.

I think you would be better served to re-sell the wheels for the price you paid and purchase the correct size...if you want to do the wilwoods...don't buy wheels until you have done those brakes...otherwise consider the baer or the SSBc for brakes if you buy wheels first to avoid multiple purchases.

You could take the wheels to a shop and get an estimate for them to modify the wheels for more backspacing....they might be able to take .5 off the inner hub...but you wouldn't know unless you asked.

 

[Luminox]

According to my research 205 is the lowest and my father confirmed that just now. I'm going to do some measuring tonight, thanks a ton for the help.

 

[sunburst gold]

Just out of curiousity, Luminox, how much is that body work (fenders, etc.) that you mentioned costing in your area??

 

[TT670]

This is a 65 with 245/45/17's on all 4 corners, 4.75 BS I did have to roll the front edge of the front wheel opening on the drivers side only, thats due to a issue with the car not wheel/tire fitment. Every other opening is just as ford made it.

 

[TT670]

deleted

 

[tjm73]

Those factory 17x8" Mustang wheels have 5.72" of backspace. Where are you getting the 4.75 number?

 

[TT670]

1" spacers. 5.72 -1" = 4.72. close enough to 4.75 for me. Actually Ive got a 68 cougar 9" rear thats 1 inch wider per side so I do not have spacers in the back. Im shortly swapping to front brakes that widen the track width so those cheesy spacers are coming off the front too.

 

[cardude]

not th hijack the thread, but on the same subject since the 4.75 is so close, would a 4.5 with 235 / 45 still be close with a lip bend?

thanks

 

[TT670]

I think you would either need to bend and/or trim the lip or run a bunch of neg camber to cleat the fenders with a 4.5 backspace.

 

[Luminox]

Well on my 66 Coupe with only a Shelby drop 4.25 BS Edelbrock 454s with 225/45/17 on back fit and I could have gone to a 235 easy and on the front I put 205/40/17 which are to small and could have easily gone to a 215/45/17 and had a good inch to spare. The 225/45/17s fit up front but filled it up quite a bit. I'm running drums for the time being but in the future I think I will move to discs since I have a lot of room. The front is a good 1/2 inch inside the lip... I drove the car with 4 people in it last night, not a single rub at any speed or bumps, I was amazed myself.

Anyone have an idea on how much a SSBC disc brake kit adds in terms of front axle length?

And to Sunburst, I'm having Quarters, Fendors, Doors, Quarter Trunk drop offs, front and rear valances and changing the car from Red to Sonic Blue.

Thanks for everyone that helped. My only wish is that I would have gone to a bigger tire up front at least a 45 series but I will change that next time.