Disc Brakes & 18" Wheels

[lkt1954]

This may be a dumb question, but here goes. Since spring is here I am starting on a 69 GMC pickup and part of the upgrades are 18" wheels. I just finished a 67 Chevelle and when I went to 18" wheels, I had to go to a big brake kit for the bigger rotors ( that meant replacing a just bought standard disc brake kit).

My question here is there a big brake kit for a 69 GMC or are the rotors large enough to look right and not like poker chips behind 18" wheels?

Thanks
Larry

[willyCJ]

I'm probably not the best person to answer this, but I'll tell you what I can... I like the poker chip analogy btw.

I'm not aware of anyone making a spindle designed for big brakes, they typically are designed around the 1.25" thick rotor that was used 71-87. This rotor/caliper setup was designed to clear a 15" wheel. Unless there is someone making a caliper to fit a bigger diameter brake, I don't think there are any options. Without a larger caliper, you wouldn't be able to fit a larger rotor.

I'm still digging the poker chip analogy, everytime I say it I just laugh.

[rex01atv]

Check into CPP they have 13'' and even 14'' disc brake kits for 67-72. You will have to use there spindal, which will narrow your track width up to an inch on each side. Ther is a article in this months classic trucks! Hope this helps.

[N2TRUX]

Do a Google search on disc brakes and you will find several companies that offer big brake kits for your truck.

As mentioned CPP recently released a version that looks great. Be aware that there have been concerns over customer service with them. We hope to have a rep from their company visit the forum soon to address that concern.

Larry- You may want to look at the option of an 18/20 combo or 20's all around. They might be a more aesthetically correct combo for your truck.

[lkt1954]

Thanks for the input. I did look up CCP and I have dealt with them before and while their customer service can suck, they do have some good products. To me their downfall is the lack of good instructions. I will continue to search for other companies.

Thanks again

Larry

[lowrollin70gmc]

The stock rotors are 12", so they don't look too bad behind 18" wheels but start to get small in 20s and 22s.

Off topic: any pics of the brakes on the Chevelle, I'm tossing some on my car in the fall.

[Scottshotrods]

we can help you out we have a big brake kit from
wilwood our kit will come
with a dropped spindal for your truck.
we have 12-13-14 inch rotors 5on5 rotors with the
kit as well.
Call us up at the shop
(805)485-0382
justin
www.scottshotrods.com

[N2TRUX]

Justin- How much drop are the spindles? Been looking at big brake options myself and it seems everyones kit offer 2.5" rather than 3"

[Scottshotrods]

The spindal we have does have a 2.5 drop with the kit
we offer.

We have a 3 inch dropped
spindal we have been working on to go with the wilwood brake kit.We are
not done with it at this time
Justin
www.scottshotrods.com

[N2TRUX]

Cool. I guess I could run a 2.5" and get another .5" elsewhere or just wait for your 3"..

[AceX]

McGaughy's now offers a front big brake kit. They are an awesome company with top notch products and customer service. They come attached to a 2.5" drop spindle with a 13" rotor.

[lkt1954]

Thanks for all the information. I am working on looking into the different places that can help. lowrolling70gmc, here are a couple of pictures of the chevelle with big brakes from CPP, as previously mentioned their customer service/instructions can suck, their product is OK and priced well. Thanks again.

Larry

[SCOTI]

An 18" wheel w/the stock brakes still looks ok (not poker chip territory). The rear truck drums (11" BTW) have an outside diameter of about 13" & thus occupy a similar amount of 'space' w/a 20" wheel vs. the 12" rotor/18" wheel. So, proportionally, the 12" stock discs & rear drums look consistent w/a 18/20 combo.

20's in front beg for a 13" minimum rotor . . ......

[lkt1954]

SCOTI- what you are telling me is that all disc brakes for these trucks are 12" diameter rotors. If all companies sell the conversion kit with 12" rotors then I will be ok with a sock kit and not have to go to big brakes. The chevelle pictured above has 13" front & 12" rear and you see little difference.

Thanks
Larry

[SCOTI]

Originally Posted by lkt1954

SCOTI- what you are telling me is that all disc brakes for these trucks are 12" diameter rotors. If all companies sell the conversion kit with 12" rotors then I will be ok with a sock kit and not have to go to big brakes. The chevelle pictured above has 13" front & 12" rear and you see little difference.

Thanks
Larry

1/2 ton GM trucks utilized 12" discs. They were available in the 5x5 pattern as 12"dia x 1.00"w (Lt.duty) & 12"dia x 1.25"w (HD). Most drum to disc conversions use the 12" x 1.25" rotors.

I have my TT2's mounted on a rolling chassis now. The fronts don't have calipers mounted but it would give you an idea of the symmetry of the rotor vs. 18" wheel compared to the driums vs. 20" wheel. I can get some pics in the next couple of days for you if someone doesn't already have some decent shots.

[andrewmp6]

I believe kore3 has brake kits with no parking brake tho.