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Parts list for 6 to 8 lug conversion. Is this correct?

pma4x4

pma4x4

AKA Yankeeroad
Joined
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Ok, So on the verge of being read the riot act for not searching I have searched and I can not confirm 100% what components I need to convert my 91 suburban 10bolt from 6 lug to 8 lug. All the info I have found appears to be for older models with different parts between 1/2 and 3/4 ton.

I did part number cross references and it looks like i dont need much.

Spindle (same)
Spindle bearings (same)
Locking hubs (same)
Calipers (same)
Backing plate (unknown)

It looks like I just need to change the rotor and hub to 8 lug. Is this correct?

This is for a 1991 V1500 suburban, 5.7TBI 4wd 1/2ton.
JB5 brake code

This is what I found for brake codes on CK5

JB5 BRAKE, POWER, DISC/DRUM, 6400 LBS
JB6 BRAKE, POWER, DISC, DRUM 7200 LBS
JB7 BRAKE, POWER, DISC, DRUM 8400 L85

JB5= front disc 11.86X1.29 rear drum 11.15X2.75 Vacuum-Double Diaphragm
JB7= front disc 12.50X1.54 rear drum 13.00X2.50 Vacuum-Double Diaphragm
JB8= front disc 12.50X1.54 rear drum 13.00X3.50 Hydraulic-Hydro-Boost
JB7 is basically Dana 60 Front disc with the smaller 14FF drum brakes with a vacuum booster and JB8 is Dana 60 front disc with the Large 14FF drum brakes with Hydro-boost.
 
Ok,

1/2ton JB5 brake rotors are 12" Dia and the 3/4T rotors are 12.5" Using the same caliper but different backing plate to make up the difference in rotor size which means i have to grind calipers ot clear 15" rims

What with a 3.75" offset on a 15x8 what spacing would I need to NOT grind calipers?


How am I doing so far?
 
I think you're right about the hub & rotor...I've been collecting parts for my swap. I'm running 16" wheels, so I don't know about your second post. here's a complete step by step how to...:thumb:


http://coloradok5.com/8lugconversion.shtml


fyi, 1/2 ton & 3/4 ton hubs are totally different...1/2 ton are 1 piece, 3/4 ton the rotor is seperate from the hub.
 
All the 1/2 tons I have seen ford and chevy have been two pieces pressed together with the lug studs.

I saw that write-up before but was taking it with a grain of salt for A) being a Dana 44 and B) being the older outers.
 
You will also need the 3 quarter ton caliper brackets and lugs nuts and studs. I am not sure about the caliper grinding I run 16.5 inch wheels myself.
 
Its likely you will need to grind the backing plate ears too. I didnt want to do this so I bought blackbird brackets. I have 15x10s with 4" bs and had to grind a little off the calipers...take your time, its easy. Just do it before you mount the tire to the rim! It makes the multiple mounting/dismounting easier.
 
Hey nutt7. I was trying to send you a private message but I tried three times with the message system saying no sent messages, if you got them let know and sorry for the spam.

Just wondering if you are available Sunday for me to stop by and pick those brackets?
 
Did you get everything needed? I have some 3/4 ton rotors/hubs (No lockouts).
 
Im still looking for hubs n rotors if the rotors are still good. But shipping would kill.

unless there is anything you are looking for in trade truck or non truck stuff. Stuff that goes bang. PM me.
 
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