Using Existing Disks w/ larger Birfs

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Mar 26, 2005
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I have a '74 FJ-40, that back in March I converted to 4 wheel disks. I used the MAF kits to do so, and really like the Wilwood calipers, and DBA discs on the front. Lack of future planning though has created a possible problem. I wish to change my tires in the next year from the 31"x 10.5 that I have now to a 34"x10.5" LTB. I think I'll probably need to upgrade the birfs to a newer style since my wheeling is mostly mild to moderate......not sure about that though. I do get some body damage sometimes.....not sure if that's moderate. Anyway, heres the ?:
If I upgrade the birfs w/ larger knuckles, can I still use the adapter plate I got with the MAF kit, so that I can keep the calipers and DBA discs?

TIA,
Doug

Sept '74 FJ-40
'86 FJ-60 2F
4 Wheel Discs
Everything else- stock
 

Mace

rock scientist..
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The spindle size is the issue.

I do not believe you can go to longs..

You can however have your coarse splined birfs sent out to longfield. But that is a bit of a waste IMHO

If you do not lock the front you will probably be okay with the drum stuff even with the 34's
 

Mace

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ARB is the same for a 74 no matter what Birfs you have in it.
 
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I have a '74 and many years ago I went to disc brakes, but I made a bracket and used the '74 knuckles, later I wanted to go to the truck birfs, so I checked the truck and '74 knuckles and they are the same except for the ears for the calipers and the spindle bolt hoes are larger, I drilled mine out and tapped them for the truck spindle and did a little grinding to allow the truck birf to go in and all wrks great for years.
 

Poser

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mrgadget said:
I have a '74 and many years ago I went to disc brakes, but I made a bracket and used the '74 knuckles, later I wanted to go to the truck birfs, so I checked the truck and '74 knuckles and they are the same except for the ears for the calipers and the spindle bolt hoes are larger, I drilled mine out and tapped them for the truck spindle and did a little grinding to allow the truck birf to go in and all wrks great for years.


So what hub, NOT LOCKOUT, are you using then...disc brake?


What rotor?
 
Joined
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Messages
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SW Kansas
This is all good information. I suppose, I should have included a long term plan for this vehicle in my first post. As my tires get larger, and I do wish to lock the front-end eventually. I thought I would need to install longfields, or newfields. I think I've read elsewhere though, that to install those you need a newer style knuckle and hub. I also wish to do a SOA conversion this spring with an OME Susp (no spring lift). While doing a cut -n- turn, I figure I can replace to the newer style knuckles to accept the longfields or newfields.
OK...That is the plan......Now

1. What can I do to keep the Wilwood calipers from the MAF kit?
2. Since there is a newer hub(splines), can I use the same DBA disc?
2a. If not. Is there another DBA disc that will work on the newer hub?
3. Previous post mention truck(mini truck) knukles. Will those knuckles allow for newfields or longfields
 
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