Changing to BBP on 83/4
- Thread starter LarryPapa
- Start date
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grumpuscreature
Resident Curmudgeon
You will need backing plates and brakes from either a 10"X2 1/2" ('65-'74 B body) or 11"X3" backing plates and brakes from the same year C body. You will also need new axles drilled for BBP or have yours redrilled if there is space for the new pattern.
moparisbest
Well-Known Member
dont redrill it dont leave much meat on flange best bet is to find a set of non tapered axles from truck are others like b body and have them cut and resplined i payed 100 bucks for truck rear and 200 to have them cut down and resplined and if you going to spend the money to do that look on ebay they have new set of axles with the green bearing instaled for like 300 bucks but then you will still need the brake backing plates and that may cost you another 100 bucks so either way you looking at about 400 bucks to have it done i just went threw all this last weak so good luck
I changed mine over to BBP .
Bought new axles cpl. with studs ,bearings ,etc.
I found an 8 1/4" axle from a b-body on the local craigslist that provided the rest. Was a good deal,it seems nobody wants an 8 1/4" for a b-body? So I got backing plates,drums,hardware,and shock plates .Everything fit great !
Took the rest to the recycler and got some of My $ back !
Bought new axles cpl. with studs ,bearings ,etc.
I found an 8 1/4" axle from a b-body on the local craigslist that provided the rest. Was a good deal,it seems nobody wants an 8 1/4" for a b-body? So I got backing plates,drums,hardware,and shock plates .Everything fit great !
Took the rest to the recycler and got some of My $ back !
belmateo
Well-Known Member
You can have your axles and drums drilled for the BPP without the expense of backing plates and drums etc. They work just fine and if you ever decide to go back to 5X4" you can!
Call Cass (Doctor Diff - http://www.doctordiff.com ) and get him to make the axles for you. He can make them any length depending on bearing choice and center section (with or without thrust spacers,thrust block,etc). My guess is that if you are still using tapered adjustable bearings on the axles, then you have the center spacer(s), or thrust buttons, in the diff because this is what the axles butt against for correct end play. There are several threads regarding the thrust block/spacers and using "green bearings" vs. the tapered adjustable bearings. Moser Engineering's BBP "A body" axles with green type bearings are too long to be used with the diff spacers installed, and then you get unwanted side load on the bearing, which will prematurely kill them. You could carefull remove the bearing adjuster off your current passenger axle and then have new tapered bearings put on your new BBP axles if you want to stay with the adjustable bearings, this will allow you to leave the diff alone (spacers stay inside).
Brakes can be any 10x2.5" from any mopar with BBP. I got the backing plates for mine off an '89 Dakota that had an 8 1/4" rear and the drums + internals off an 85 Chrysler 5th Ave that had a 7 1/4". Cordoba, Aspen, etc will all work. You will need the backing plates, internal junk and the drums. IMO the 11x3 rear brakes are too heavy and not needed.
Brakes can be any 10x2.5" from any mopar with BBP. I got the backing plates for mine off an '89 Dakota that had an 8 1/4" rear and the drums + internals off an 85 Chrysler 5th Ave that had a 7 1/4". Cordoba, Aspen, etc will all work. You will need the backing plates, internal junk and the drums. IMO the 11x3 rear brakes are too heavy and not needed.
fishy68
Tyr Fryr's Inc.
This is right. I'm having Cass make up a set of axles for me right now that'll bolt right in using the stock brakes all except for the drums which I can re-drill. He even said they'd work without removing the thrust pins.
66cuda-s
Well-Known Member
Question:
Are backing plates different between SPB and BBP for 8.75 axles? If so, why?
Thanks.
Are backing plates different between SPB and BBP for 8.75 axles? If so, why?
Thanks.
Yes, that is an option if you want to stay with your old brakes, just redrill the drums. My SBP 10x1.75" drums were bad so I changed to the BBP 10x2.5". Moser can also make axles to work with your redrilled SBP brakes but you have to tell them what brakes you are using. Next time I will call Cass because his prices are lower and service is more personal with the work being done, but I will say that I am happy with the Moser axles after figuring out the spacer issue with some help from this forum and other people I talked to. In 1995 I bought the same exact Moser axles for $200 with bearings installed and put them in, never removing the diff spacer, and I remember the bearings being tight.
BBP brakes are wider (10x2.5" vs. 10x1.75"), so the backing plate goes deeper in toward the car to account for the brake width. Whichever drum you use needs to be mated with the correct depth backing plate. I think Mopar also made 10x2" but I am not sure which years/models, maybe someone can verify that.
66cuda-s
Well-Known Member
BBP brakes are wider (10x2.5" vs. 10x1.75"), so the backing plate goes deeper in toward the car to account for the brake width. Whichever drum you use needs to be mated with the correct depth backing plate. I think Mopar also made 10x2" but I am not sure which years/models, maybe someone can verify that.[/QUOTE]
Thanks, most informative.
Thanks, most informative.
Another issue is the flange standoff between the BBP and SBP.
The BBP sticks out further from the bearing retainer than the SBP stuff.
As someone mentioned. Find a BBP rear axle and snag everything off of it for your rear brakes and you're good.
The BBP sticks out further from the bearing retainer than the SBP stuff.
As someone mentioned. Find a BBP rear axle and snag everything off of it for your rear brakes and you're good.
varlo
Joe- Long Island, Oakdale
arent the rear brake assemblies off other modern day vehicles interchangable for this swap? i could of swore i saw something a while back
The Moser axles stick out +1/4" on each side vs. the SBP axles. This could be an issue with certain backspace wheels, but shouldn't be a problem unless you are running tight tire clearances already.
My brakes came from 89 Dakota and 85 5th Ave. They are 10x2.5"
Iggy
Iggy
Yukon makes a great set for what you are doing. get some backing plates and buy all the rest kits are available but is for a newer version like a lebaron or 5th ave.I used Brays auto in Windsor. He was a great help and knew what to get. His name is Tom
Charrlie_S
Well-Known Member
I drilled my axles and drums for the BBP. I used the long screw in studs, and there is plenty of room. Also have a set of small bolt pattern axles, with long studs. I have a set of 8 x 22 x 13 SBP wheels/slicks for 1/8 mile, and 6 x 27 x15W BBP wheels/slicks, for 1/4 mile. I just swap axles and wheel/tire, same brake drum. Both sets of axles have the green bearings. About 15 min to change "ratios".
I have a drill fixture to do this.
PS: I also drilled my front drums for BBP.
I have a drill fixture to do this.
PS: I also drilled my front drums for BBP.
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