Magnum 400 wheels on 78 king cobra * please help *

scooterstangs

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Aug 18, 2020
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Hello everyone. I am new to this site. I recently purchased a 78 Mustang king cobra and the wheel/tire size from the factory makes this car look borderline embarrassing. So much room in the wheel wells that need to be addressed. I want to buy the magnum 400 wheels as it is quick upgrade without changing to a five lug. I called the company that makes them and CJ pony parts and both don’t have a clue on what tire size to use. Has anyone tried these wheels on there Mustang II? I think the right combination will make this car look awesome. The wheel wells definitely need a taller and wider tire to get the look I’m after. I‘m not opposed to using a spacer with these wheels. Any help would be much appreciate! Thank you!
 
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LILCBRA

I wish I didn't have all of these balls in the air
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Dec 6, 2005
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Hi and welcome!

At the top of the II forum homepage there are thread stickies. Hit the "best of tech" thread and the first link is the wheel/tire combos known to fit. That section, while pretty long, would be your best bet to check and see what different people have used and what they may have had to do to get their specific combo to work. Here is a direct link:

Now that being said, if you're looking to keep them the same size at all 4 corners, I'd think a 225/60-15 would probably get you there. But you may find areas that you'll run into clearance issues. I'd venture to say the rear would be just fine as I run a 265/50-15 on the rear of mine. The front on the other hand, is where you may have issues. I run a 165/80-15 on the front and had to "modify" the body seam after removing the well liners. But my car is lowered in the front, your situation may be different.

20190524_203006.jpg
 

scooterstangs

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Aug 18, 2020
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Thank you for responding : ) . you are running 265/50-15 on the rear, what is your back spacing on the wheels you are using and are you using a spacer? thanks
 

LILCBRA

I wish I didn't have all of these balls in the air
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Back spacing on the rear of my car is 4" or 4-1/2", I don't remember off the top of my head. I may have listed it in that thread I linked. :shrug:
 
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LILCBRA

I wish I didn't have all of these balls in the air
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I am not using any spacers. My setup starts on page 9, post 177:

Alright-I FINALLY broke down and bought the new wheels and tires, well rear tires as of right now. I don't have the fronts yet, no one has the size in stock (165/80-15's on 15x4's), so they will have to wait until next weekend. But, I have the rears- 15x8 with 265/50-15's. I have to say I love it!! Anyways, since there are only a few pics with this size, I thought I would post the few I took of mine earlier today. Sorry for the relatively crappy quality-I took them with my phone. If anyone is interested, I can take a few more with my actual camera.

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:rock: :D

They are 4.5 backspacing.
 
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scooterstangs

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After really not finding a 4 lug wheel I wanted. I decided to do a 5 lug conversion. I have my heart set on the magnum 500s as the 4 lug magnum 400s were not doing it for me. I used the speedway Granada style rotors with the GM calipers, a nice complete kit from speedway. The rear I am replacing the axles to a five lug. Having a hard time finding the axle bearing retainer gaskets and I believe I am going to use 1987 Ford Ranger 2wd rear drums. Once I have completed the conversion, I will see what tire/ wheel combo I can go with. I’m still thinking 15in chrome magnum 500s with the cobra center cap. Hopefully it will be completed soon and I will share pics. If anyone knows where I can find the bearing retainer gaskets, please let me know! Thanks
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
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Welcome to the forum. Pictures of your car would be great.
I tried to find the gaskets also. No success but will make my own when the time comes.
 

scooterstangs

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Aug 18, 2020
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Here it is. Sorry for the picture orientation. I have, what I believe is the fel-pro part number, but it is no longer a good number. I will post that number later.
 

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LILCBRA

I wish I didn't have all of these balls in the air
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Rock Auto was wrong?! Shocking. (That's sarcasm in case anyone was wondering...) That was the best I could come up with in a quick search and thought it looked right. I have an old 8" out of my old wrecked coupe sitting in my shed that I've had the axles out of, that piece looked familiar enough. Then again, it's been a million years since I've taken it apart. Past that, I'm not sure where to look. If you have a Napa near you, maybe they can help you more so than an Oreilly's or an Autozone. Seems I've always had better luck finding II specific parts with Napa than anyone else. Then again that was a small town Napa in Amish country in Iowa where they were used to looking up obscure, hard to find parts. :shrug:
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
593
418
73
64
Minnesota
This piece?

1601419181116.png


The pic says it all. It's a Fel-Pro 55035 according to them. $1.86 a piece.
When I get to take mine apart I'll find the replacement for sure. It looks like there are several out there that are similar. Thanks once again.
 
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MustangIIMatt

I need something stupid to play with
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RTV silicone is your best friend, if you don't get such a gasket...
View: https://www.amazon.com/Permatex-81182-Gear-Gasket-Maker/dp/B0023GM2KK/ref=asc_df_B0023GM2KK/?tag=hyprod-20&linkCode=df0&hvadid=198091122898&hvpos=&hvnetw=g&hvrand=10026223513508739951&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027400&hvtargid=pla-406710904314&psc=1


Those two RTVs in particular are "friendly".

The ONLY thing Chrysler got right when I worked for them (besides the marketing and styling on the LX-platform cars and the Ram pickups) was their specialized RTV formulations that resisted certain fluids. Permatex either made them for Mopar or they copied the idea. The ATF and gear-oil resistant formula RTVs are spectacular from both brands.
 
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