[rohrt]

This summer I would like to convert my tempest over to disc system.

I'm taking the advise of sticking with factory parts on the spindle and caliper brackets and purchasing the rest as needed to complete.

1. I was told the 64 spindle has a different upper boss bolt size then other spindles? Should I consider a different spindle because of this?

2. Are A and F body spindles the same?

3. I understand the upper boss needs to be shaved down. Does this need to be done at a machine shop to be in plane with the lower bolt height?

[george kujanski]

I'll take a shot @ #3...at least on my '67. It needed to be shaved down but just to bolt on the dust shield. On a drum system the shoe anchor bolt goes into the boss...not used with disks for anything but the dust shield.

george

[Scott Thelander]

hmmmmm

on my discs it holds the caliper bracket also

some spindles and steering arms use 7'16 some use 1/2 " on the lower 2 bolts

yes the upper bolt is a different size between a gm disc n drum spindle from what I have found

67-72 a body disc and 67-69 f body disc use the same spindle ,,, 69-72 GP nova 70-72 monte

[ZeGermanHam]

I've seen a number of people attempt to do disc brake conversions by purchasing parts piecemeal like this. It seems like it takes them twice as long (or longer) to do all the research needed to buy parts individually, and they often run into compatibility and fitment issues once they start bolting parts together.

So, why not just buy a complete kit?

[Scarebird]

64-72 drum Pontiac "A" are all 1/2" upper, 7/16" lower.

All OEM disc those years are 5/8" upper, 1/2" lower and the upper boss is about 0.375 shaved.

To reuse your stock spindle you will need one designed to use that spindle.

[rohrt]

Originally Posted by ZeGermanHam

I've seen a number of people attempt to do disc brake conversions by purchasing parts piecemeal like this. It seems like it takes them twice as long (or longer) to do all the research needed to buy parts individually, and they often run into compatibility and fitment issues once they start bolting parts together.

So, why not just buy a complete kit?

From the information I gathered (Not that its right) is the factory spindles were forged or hardened (IDK) by a superior induction process that GM used. Making them a much better/safer choice then any factory style after market spindle.

[66sprint6]

We bought the parts from a local guy for cheap when the opportunity arose. Basically everything between the upper and lower A-arms on a typical 68-72 A-body. A true comprehensive bolt in except for the service parts like hoses, etc. You should be replacing all that anyway.

[rohrt]

I remembered this old video from way back. I thought this was more common procedure? Maybe not.
https://www.youtube.com/watch?v=Xhj2BGXAW80&t=874s

Its a little more "Hackish" then I like but I see the hardware stores sell correct spacers. Speedway sells a cheap kit without the spindles and even Master Power talks about Factory spindles being superior.

I have some backing plates and plenty of drum spindles.

Ebay prices for factory parts are up there.

[Scarebird]

What size/type wheels are you going to use?

[rohrt]

Originally Posted by Scarebird

What size/type wheels are you going to use?

I run 14s currently. I know I would need new disc compatible 14" rims.

[Scarebird]

Not necessarily. Our setup will clear the 14" drum wheels.

[Lemans64]

I do have a complete list of stuff required if swapping over from drum to disc.
Also shows how much to cut off your drum spindle. But have to send as email. too large to post here I believe.

[donziboy]

Scarebird
Question will your system work with original Hurst wheels? Considering going duel master cylinder and front disc setup.
Thanks

[Scarebird]

I have not tested one yet.

[donziboy]

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