Big Bolt Pattern Conversion

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SGlez10

68 Barracuda
Joined
Sep 17, 2020
Messages
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Location
Carson, Ca
Hi guys. My 68 Barracuda currently has a small bolt pattern with disc brakes. I am looking to convert to a big bolt pattern. Goal is to have 255 in the back and 245 in the front. What do I need? Where can I purchase big bolt pattern spindles?
 
Mustang parts on my Barracuda????? I don’t know about that one. But I’ll definitely check out Doctor Diff thanks.
They both use the Kelsey-Hayes disc brake system, A bodies with a 4" bolt circle and Mustang with 4.5". It's just a matter of adapting the 4.5" rotor to your spindle, all the rest of the hardware is the same. If you want to spend a ton more money on aftermarket "kits" (some of which use GM parts, too), go ahead. The Kelsey-Hayes are arguably a better setup than even the later ('73 and up) A body system, which is the most popular route to a 4.5" pattern.
FYI, changing the rear to 4.5" involves non-factory aftermarket axles, so you need to get over it. None of the stuff comes from the Ford parts counter.
 
Ahh ok I see, thank you for this information.
They both use the Kelsey-Hayes disc brake system, A bodies with a 4" bolt circle and Mustang with 4.5". It's just a matter of adapting the 4.5" rotor to your spindle, all the rest of the hardware is the same. If you want to spend a ton more money on aftermarket "kits" (some of which use GM parts, too), go ahead. The Kelsey-Hayes are arguably a better setup than even the later ('73 and up) A body system, which is the most popular route to a 4.5" pattern.
FYI, changing the rear to 4.5" involves non-factory aftermarket axles, so you need to get over it. None of the stuff comes from the Ford parts counter.
 
Most go with the new axle and larger drum setups these days.

Way back, a lot of folks had their SBC axles plugged and redrilled to 4-1/2" BC. As you can see here, the redrilled 1/2"-20 R holes get close to the edge of the stock flange. The redrilled holes need to be perfect on the locations or you'll likely have issues.......

1666892956062.png


You'd also need to redrill the drums. The hole location is not quite as critical as the axles as the register will locate it.........

1666893827561.png


FWIW, Moser sells stock length BBC axles for the 10" X 1-3/4" drum set up. A thicker flange compared to the stocker.........

1666894689812.png
 
Most go with the new axle and larger drum setups these days.

Way back, a lot of folks had their SBC axles plugged and redrilled to 4-1/2" BC. As you can see here, the redrilled 1/2"-20 R holes get close to the edge of the stock flange. The redrilled holes need to be perfect on the locations or you'll likely have issues.......

View attachment 1716003380

You'd also need to redrill the drums. The hole location is not quite as critical as the axles as the register will locate it.........

View attachment 1716003393

FWIW, Moser sells stock length BBC axles for the 10" X 1-3/4" drum set up. A thicker flange compared to the stocker.........

View attachment 1716003398
Oh man, umm… I think if I can’t find what I need I’ll buy new and sell what’s on there now. Thanks for this information though.
 
Oh man, umm… I think if I can’t find what I need I’ll buy new and sell what’s on there now. Thanks for this information though.
What are you wanting for the rear? Disc or drum? I have a nice 10" set that includes backing plates, shoes, hardware, wheel cylinders and drums. Wheel cylinders might need kits, but they are pretty clean looking. Send me a pm if you're interested. I can send you some pictures.
 
What are you wanting for the rear? Disc or drum? I have a nice 10" set that includes backing plates, shoes, hardware, wheel cylinders and drums. Wheel cylinders might need kits, but they are pretty clean looking. Send me a pm if you're interested. I can send you some pictures.
Disc for sure.
 
Ok cool. You won't need my stuff then. lol I would certainly contact Cass at Dr Diff. He can fix you up.
Yea I plan on calling him tomorrow. My cars almost ready. Wheels up next. As you can see car is in need. And I want 255’s in back and 245 in the front.

41B193EB-05E5-4A0E-831F-C1EF54B08E08.jpeg


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2ECB0363-4EB8-4C67-A7FA-C9E0CB284ED1.jpeg
 
Good lookin car! I used to not like notchbacks much but they've really grown on me over time.
I’m going to PM you. Maybe keeping drums on rear is ok. I have disc in front. Let me see what ya got. And if you want to send pics I can give you my email in pm
 
Good lookin car! I used to not like notchbacks much but they've really grown on me over time.
And thank you for the compliment. That seems to be the trend as of late. I’m hoping the notchback gets the credit I personally believe it deserves. Even fastback owners completely dismiss the notchback and put themselves above it. I’ve always liked the Coupe so it’s nice to hear the compliment.
 
And thank you for the compliment. That seems to be the trend as of late. I’m hoping the notchback gets the credit I personally believe it deserves. Even fastback owners completely dismiss the notchback and put themselves above it. I’ve always liked the Coupe so it’s nice to hear the compliment.
Isn't the notchback a little lighter than the fastback? I think they are. That's always a plus.
 
That car looks badass in black with black wheels.

I have a set of bbp discs and spindles from a '73 if you're interested. Control arms, too. Pm me if interested
 
That car looks badass in black with black wheels.

I have a set of bbp discs and spindles from a '73 if you're interested. Control arms, too. Pm me if interested
This is what I did to my 66 Valiant Sedan
 
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