Formula101

I have and 89 formula with a drum brake 10 bolt non posi. I just picked up a 9 bolt with disk 345 and posi to swap in. Who Carries calipers rotors and any other parts if needed. I also have a 93 disk brake 10 bolt will the calipers and rotors swap over? They look like better brakes then the 9 bolt

sofakingdom

iTrader: (1)

Which brakes does the 9-bolt have? (Iron caliper Saginaw, or aluminum caliper PBR)

I'm betting the 9-bolt has the Saggy (88-back) stuff. Because, if it had the 89-up PBR, it would look EXACTLY the same as the 93, because … it pretty much is.

Yes the 93 stuff will swap onto the 9-bolt. Only potential issue I know of is the backing plates, in particular the spacing of the caliper carriers to the rotors. Might have to work on that a little, not insurmountable, just requires paying attention. Be prepared for more fun than you care to think about however, when it comes to R&Ring the 9-bolt axles. Specifically, locating new seals. DON'T take anything apart until you have those in your hands. NOT, "can't be that hard"; NOT, I think I saw em"; NOT, "they're on this or that web site; NOT, "on order"; IN YOUR HANDS.

Formula101

Thanks for the response. The 9bolt does have the metal gm calipers not the aluminum ones that are on the 93. I dont think I'd be stuck with the 9 bolt as I bought it from a salvage yard with a good reputation. Didnt realize the 9 bolt parts where so hard to get. I'm rethinking this plan now and may just spend the money on building my 10bolt.

KyleF

The 9 bolt 3.45 is a great choice. Favorable ratio and better set up than drums.

I don't know why people say 9 bolt parts are hard to find. They are not. People like Hawks have salvage yards full of parts now, there are websites like 9 Bolt.com, and you will be surprised what you can get locally sometimes. You have to also remember there are Holdens that were built using this 9 Bolt.

I agree with this part 100%. You do have to still consider these are 30 year old cars. You may have to have parts shipped in and wait for them. Unless you are prepared to have it sit down for a few weeks or it is a months long project, don't expect to be able to get all parts in a day or two. Don't take what I am saying, not hard to get, to mean they can be had quickly.


I see O'reilly's has the calipers in stock at their warehouse, available 2-3 business days for store pick up or to your door delivery, $58.89 each($15.00 core)- Same for the rotors at $44.99 each. I went with Stillen Pads/Rotors on mine

You will also need to change the spring in your proportioning valve - there is a lengthy thread on that near the top of this page
You will need the proper ebrake cables too.

Might be a wise idea to call up a place like Hawks and see if you can just get the cables and caliper assemblies. You will need the return springs, actuator levers, and maybe a few other odds and ends either way you go depending on what is on each axle. The one thing the 9Bolt has going for it is it already has the Idea ratio for a TPI car and an large improvement for a TBI car.

The 93 has a favorable brake set up, but will be more work to get in as far as needing backing plates... but it is essentially the 1LE package and just getting the parking brake cables for the 1LE may work. Please do a search and find a thread where someoen has done this swap. It is pretty common, shouldn't be hard to find to validate what cables they used or any other items I may not be aware of. I have not done a 4th gen axle swap.