[rtyauch301]

as the title says... 70 pontiac full size B-body rotors were can i get them ... advanced said the 71's would fit but i just dont believe it from someone that has never tried....

[enjenjo]

The later rotors fit.

[chieftain]

69-70 Pontiac brake rotors are on there own. Nothing else will work. The outer bearings bearings are differant for one. Have you actually tried this?

69-70 uses a #2 outer and #5 inner bearing
71-76 and most other full size use a #3 outer and #5 inner.

Most gm's use a combination of 2 and 6 or 3 and 5.

#2 .750 id, 1.781 od
#3 .8437 id , 1.969 od
#5 1.375 id, 2.563 od
#6 1.25 id, 2.328 od
each maker has differant prefixes, but they usually use the same basic number.
Sorry to get so technical, I just wonder how your getting past the bearing differance?

Back to the original question, it seems all the available new rotors have run out. There is one company , Scarebird that makes disc brake brackets for the non mainstream cars. At one time someone was looking for him to make some brackets for those spindles, yes it sounds funny to make a disc conversion for a spindle that already has disc brakes , but since no rotors are available maybe an option with using a ready available rotor or cut your rotor down to a hub and slip a rotor over it. .

Another option would be to find a pair or drum spindles and put his bracket that is already made for those and convert those over to disc brakes. I have an older kit that I have on 63 spindles available that would work on your 70. The old popular swap before disc brake kits came out was to put the 69-70 setup on the earlier 60"s Pontiacs. My 63 drum spindles reuse the drum hub and use a 11" rotor over the top . The newer kits use a 12" rotor like the original rotor.

Or find a good used set ?

[freedom53]

i belie ve that I read somewhere that vette rotors can be used on the original hubs. these hubs use a different bolt that presses thru the rotor from the back side into the hub and mounts the wheel directly to the hub. wish I could remember where I saw it.

[enjenjo]

Originally Posted by chieftain

69-70 Pontiac brake rotors are on there own. Nothing else will work. The outer bearings bearings are differant for one. Have you actually tried this?

69-70 uses a #2 outer and #5 inner bearing
71-76 and most other full size use a #3 outer and #5 inner.

Most gm's use a combination of 2 and 6 or 3 and 5.

#2 .750 id, 1.781 od
#3 .8437 id , 1.969 od
#5 1.375 id, 2.563 od
#6 1.25 id, 2.328 od
each maker has differant prefixes, but they usually use the same basic number.
Sorry to get so technical, I just wonder how your getting past the bearing differance?

Back to the original question, it seems all the available new rotors have run out. There is one company , Scarebird that makes disc brake brackets for the non mainstream cars. At one time someone was looking for him to make some brackets for those spindles, yes it sounds funny to make a disc conversion for a spindle that already has disc brakes , but since no rotors are available maybe an option with using a ready available rotor or cut your rotor down to a hub and slip a rotor over it. .

Another option would be to find a pair or drum spindles and put his bracket that is already made for those and convert those over to disc brakes. I have an older kit that I have on 63 spindles available that would work on your 70. The old popular swap before disc brake kits came out was to put the 69-70 setup on the earlier 60"s Pontiacs. My 63 drum spindles reuse the drum hub and use a 11" rotor over the top . The newer kits use a 12" rotor like the original rotor.

Or find a good used set ?

I misread 70 as 71. It still can be done by using a set 34 outer bearing that fits the spindle and rotor, .8437 ID 1.8710 OD, and a spacer on the inner bearing. Another solution is a drum brake hub with a Toronado to 1976 rotor.

[rtyauch301]

Originally Posted by chieftain

69-70 Pontiac brake rotors are on there own. Nothing else will work. The outer bearings bearings are differant for one. Have you actually tried this?

69-70 uses a #2 outer and #5 inner bearing
71-76 and most other full size use a #3 outer and #5 inner.

Most gm's use a combination of 2 and 6 or 3 and 5.

#2 .750 id, 1.781 od
#3 .8437 id , 1.969 od
#5 1.375 id, 2.563 od
#6 1.25 id, 2.328 od
each maker has differant prefixes, but they usually use the same basic number.
Sorry to get so technical, I just wonder how your getting past the bearing differance?

Back to the original question, it seems all the available new rotors have run out. There is one company , Scarebird that makes disc brake brackets for the non mainstream cars. At one time someone was looking for him to make some brackets for those spindles, yes it sounds funny to make a disc conversion for a spindle that already has disc brakes , but since no rotors are available maybe an option with using a ready available rotor or cut your rotor down to a hub and slip a rotor over it. .

Another option would be to find a pair or drum spindles and put his bracket that is already made for those and convert those over to disc brakes. I have an older kit that I have on 63 spindles available that would work on your 70. The old popular swap before disc brake kits came out was to put the 69-70 setup on the earlier 60"s Pontiacs. My 63 drum spindles reuse the drum hub and use a 11" rotor over the top . The newer kits use a 12" rotor like the original rotor.

Or find a good used set ?

so i really really need some rotors if i machine down the hub what rotors will fit over i read that same article about the vet rotors some time ago and cant remember were so any help here would be great ........sorry to bring such an old thread back to life

[cobalt327]

I believe it involves using the drum spindles w/rear 'Vette rotors and longer studs- but this needs to be verified.

[rtyauch301]

thought it was just the drum or rotor hub machined down with an 70's year rear vet rotor but i could be wrong

[Jim Rockford]

you have the 5x5 BP correct?

[rtyauch301]

5X4.75 i think same bolt pattern as a 96 caprice classic borrowed a spare tire from one

[Jim Rockford]

1991 the bolt pattern for the caprices reverted to the 5x5 like the previous wagon and police package. you might be able to use some front rotors from a 91-96 caprice. alot of the b body stuff stayed the same from the 70-96.

[joe_padavano]

Originally Posted by Jim Rockford

alot of the b body stuff stayed the same from the 70-96.

No, the commonality is 1971-1996. The 1965-1970 cars are completely different.

[Jim Rockford]

Originally Posted by joe_padavano

No, the commonality is 1971-1996. The 1965-1970 cars are completely different.

I ment to type 77-96..lol I have heard alot of stuff back to 71 would work for later models, but haven't tried it.