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rim question - couldn't find answer in FAQ

sarens

Full Member
Joined
Apr 12, 2013
Messages
150
sorry I looked but most likely this has been answered, want to put 15" from F100/F150 alloy on my '71

1) they are 7.5" width will that be an issue
2) don't know backspacing, will that be an issue
3) believe my EB needs a 86.7mm (3.413") bore for hub centers, anyone know what the '90s F100/F150 rims are?
 

SHX669

Bronco Guru
Joined
Jan 9, 2009
Messages
1,997
My first impression is - yes they should work . I believe Broncos and F-150s pre 1996 all had the 5x5.5 bolt pattern with big enough center hole to accomodate locking hubs.
Is your steering linkage stock ( not uncommon for some wheels to need 1/2" spacers to work on '76 and '77 Broncos}
SHX
Oh - Ford phased out the F-100's in 1974 - the F-150 replaced it with a higher GVW as at that time with DEQ regs ; vehicles with a #6000 or higher gvw didn't have to use unleaded gas.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,355
What SHX said.
The width is not an issue, and will work with up to an 11.50" wide tire with no trouble.
Not knowing the backspacing can be an issue, but most likely you're ok with your '71. Like was said.

Either way, with a larger tire than stock, you're still likely to rub the sidewall on the radius arms. Won't hurt anything of course, but will sound like hell and rub some paint.
If you're already running larger tires, you already know all that!

Paul
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
I dont know the back spacing either but they will fit. The hub bore is the same as they used the same sized hubs up to 95/96.
 
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sarens

sarens

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Apr 12, 2013
Messages
150
thanks guys, I'm really impressed with level of knowledge on this site, this is my first EB, done other cars but never seen a site with so many educated and nice people, thanks again
 

DirtDonk

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Nov 3, 2003
Messages
47,355
Wait until you find out we've just been messing with ya though! Just kidding.
Or, worse yet, that the wheels turn out to be '97 or later metric ones. Bummer there and a no-fit for sure.

Have fun. Have you already bought the wheels yet? Or are you still looking for just the right ones for your rig?

Paul
 
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sarens

sarens

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Joined
Apr 12, 2013
Messages
150
Paul,
-love the sense of humor on here also, very high brow
-bought them yesterday, they aren't metric (deep breath when I thought about that one), '90s F150 10-hole, very clean happy with them
-all set, thanks for everything

-how is 33's with the 4:11 on the highway, what trans do you have now in there?
 
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DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
47,355
The 4.11 ratio was never a problem for me, even with the stock 3spd. I knew that the 302 was perfectly capable, and happy (if not exactly at it's most efficient?) to run in a higher rpm range. Never gave it a moment's worry as far as the engine itself was concerned.

With the old 1:1 ratio and 32" tires, I was happily cruising anywhere between 55 & 75 mph.
Hovering around 3200 rpm or so was not an issue. And seemed much less stressful when I put a quieter exhaust on too. Exhaust sound has a huge effect on perceived rpm, and the engine's happiness at said rpm.

With the slightly taller 33x11.50's, it was a little better. Right now, it's still apart waiting for the NV3550 to magically install itself!
With the stock engine, I don't think the 4.11's will be quite low enough however, since overdrive with the larger tires could still put me in an unhappily low rpm range. However, with a properly tuned and running engine, with a cam that's happy creating torque in the proper range, I think the gears will still be perfect. Even exceptable with 35's.

That's the ultimate dilemma though. With the 35's and a good running engine, will the 4.11 still be good in overdrive with the 302, or would the extra few hundred rpm of 4.56's, or even 4.88's, be better?
Time will tell.

Paul
 
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sarens

sarens

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Joined
Apr 12, 2013
Messages
150
yea I have concerns about my ratio also and getting the AOD to run in the sweet spot, going to do some more math and reading up on it, I pulled a motor/trans from a '90 Mustang GT, figure if I get the highway speed/rpm combo to match close to what the stang would have done the trans should be happy
 
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