In gathering parts and pieces for my latest project, I realize disc brakes would be a better, safer way to go but this lilttle 36 chevy pickup will be 50's/early 60's traditional and disc brakes [except the 'spensive kinmonts] weren't around yet. To slow this hemi powered hot rod down, I'll be using finned buick drums on the front and I'd planned to use the 12 inch aluminum buick drums on the back too. This is uncharted territory for me. I'm using a 57 Pontiac rear axle and would like to know if anybody has installed the 12 inch brakes on one of these rear axles? The original 57 Pontiac brakes are 11 inch which precludes me using the pontiac backing plates. Anybody ever tried using the buick backing plates on the poncho/olds rear axle? Discuss amongst yourselves...........
I had a friend (he is now deceased) who had Buick 45 Fin drums all the way around. He had a Pontiac rear also. I believe he adapted Buick backing plates to his Pontiac stubbs. He cut out the Pontiac backing plates center and put them in Buick front backing plates. All of this was done prior to his moving South. My memory of how he told me he did this may be wrong. It was 20 or more years ago.
Hey Rocky, the July 1971 issue of Car Craft is supposed to have a how-to on this subject. I'm still trying to find my copy as I want to do it too. Hope this helps. Max
All good stuff to digest...Brian, I'm working on a deal for the front buick backing plates to go on the Pontiac rear axle. If it doesn't work out for me, I may be giving you a call.
Rocky, I just got finished putting 60 Buick backing plates on my 55 Ford rear under my 31 Plymouth. There, I just filled and drilled the bolt pattern and had the center hole bored to match the Ford rear. Incidentally, I have a 57 Poncho here for the exact same reason. I put Buick drums on the front a couple months ago, and he brought it back wanting the same thing on the rear. The front was easy, just used 56 Cadillac hardware and shoes on the Poncho plates and put the drums on the hubs. The 57 Pontiac already had 12" brakes on the front. I have ran into the problem that you are going to hit; offset. With the Ford rears, the offset from the face of the housing to the outer side of the axle flange is the same as the Buick fronts. I have yet to find a suitable backing plate donor for the Poncho rear though and I have exhausted my pile of vintage backing plates. I have tried several Buick rear plates from 53-66, Cadillacs from the 50's and 60's, even Chevy and Ford trucks, etc. and none are closer than 1/4". I dont mind a little diferrence, but after 1/4" to 3/8", I dont like that the backing plate isnt in the groove in the drum. Not that it really hurts anything, but it looks like shit. The 54-56 Buick rear plate is closest that i have found, but it sits a bit out of the drum and lets the shoes hang out. Not a big problem, since the shoes I put on the front are 2 1/2" wide I was going to put 2" on the rear. Adding a couple 1/4" strips at each shoe to space the shoes away from the plate is what I'll likely do, and that will put the entire lining in the drum. The Buick bolt pattern is a lot different than the Poncho though. The center hole is larger, so it makes for an even more dificult task of centering and drilling. Deuce Roadster may have the best solution though. Due to the fact that there is a good bit of the Pontiac and Buick plates that are true flat, turning out the center of the Buick and putting in the Poncho center would allow you to not only get the pattern easy, but give a means of correcting the offset problem. I have to get this done for this fella, so I will follow up with what I do and post some pics. it can be done Rocky...just keep that in mind!
Hey Rocky...make SURE your Buick drums will fit into the wheels you want to use! I ran into this little problem only AFTER I had everything finished up. I put the wheels on and they lacked 1/8" or so pulling up. The fins hit the rim! 15 x 10 slots. Gotta turn off a bit if the fins to get some clearance.
Thanks Ray. splicing in the Pontiac backing plate centers to the buick backing plates sounds like the easiest sulution to me if I can get the offset right.
Maybe, I hope so anyway. If you'll notice though in the picture, the inner part of the fins are damn close to 1/2" bigger than the wheel Aint this fun??? Since I accidentally uploaded it, here is the front side of those 60 backing plates on a Ford rear
Rocky, I looked back over my notes and thought I'd share some of what I found. You may already know this, so forgive me if its useless. Sorryt for the length...I know I type too much The Pontiac uses a basically flat plate with a 2 3/4" spacing from the axle flange to the face of the axle housing. The 60 Buick plate is dished deep, using a spacing of 2 1/8" approximate. The front plates arent intended to use an emergency brake. The center is also very large, so to remove the center and put the Poncho center in you must remove a large portion of the Buick plate's center. The 54-56 Buick rear backing plates have the emergency brake, smaller center dish, and room in the bottom to add self-adjusters if you are so inclined. They fit the drum the same as the 60 fronts, but with the smaller center they are easier to modify. The later (60's) Buick rear plates are ugly and dont have the lip that fits the groove in the drum. So, you can't remove "all" of the dished center from the Buick to add the Poncho plate center. This will bring the plate so far outward that the drum wont go on. If you plan on swapping centers, I'd suggest (not telling you what to do) having the Buick plates chucked up true on a lathe and removing the necessary part. That way, you have a flat lip to weld the Poncho center to. I'd do the same with removing the center of the Poncho plate too. You'll still need to use a dial indicator or some other fairly sensitive measuring tool (again, a suggestion) to get the Poncho center aligned. A tape will get you really close, but the closer you can get the better. One thing many dont realize is self-energizing brakes can tolerate a fair amount of misalignment. The adjustable anchor pin allows a lot of room for error. If you get it really out of center, you can always go to an offset anchor pin too. I got a couple if you end up needing them. Your 60 plates may already have them though. I cant remember if 60 used them, but a few years of Buicks did. I'm not saying you can't do it without a lathe, I'm just saying it would be a lot easier if the cuts are made precise. I am supposed to get this car finished this week, so I'll have a bit more experience to share than just dimensions and suggestions. Sorry if I'm rambling. This is a swap I have played with quite a bit, just not on a Poncho, and I thought it was slick that you just happened to bring up a question that I am presently faced with. good luck man! Ray
hey i got a question for u guys then? I need a pair of backing plates for my 57 poncho rear end... anyone got a pair? im doing the same thing rocks doin, steve has a website with the article on it. heres the link for it : SEVES WEB LINKS there is the buick front and buick rear end etc etc... check it out! Tuck
Thanks Ray....I'll be watching your progress on this swap and Tuck, I need your mailing address. I seem to have lost it somehow. Just e-mail it to me and go wait by the mailbox but don't expect any 57 Poncho backing plates, I don't have any extras in my inventory just now.
im gonna check the yard next friday for the two of us.. .maybe i can score some backing plates. They have a bunch of 50's pontiacs, just not sure if they still have the rearends. Tuck
I have been working on a few of these swaps, and I have a bunch of info at the shop. in the mag articles they install the 53 buick plates on a ford rear if I remember right. they made a 1/4" or so spacer to go between the backing plate and the axle flange to account for the backspacing. I will try to remember to upload the article tomorrow.
Here are scans of the article for putting Buick front finned drums on an Olds or Pontiac rear. From the July 1971 issue of Car Craft Magazine.
The Jalopy Journal
