Disc brake swap problems

[Malamute]

I'm swapping drums out for 4 wheels discs. CPP kit. Finally got around to getting something done and once I got the new rotors on I could see that the studs were longer than the drums I pulled.

Went from 1" to 2 3/8" and the thread pattern is also different. I'm using Rally wheels for the time being and even if I did get the correct threaded lugs they wouldn't be deep enough to work.

What do I need to do to get this rolling? I've got a friend with a better shop and knowledge than I do and I just need to get it rolling so I can get it over to him to finish up. I thought I had it until I went to put the wheels on.

I have some pics but my camera is struggling to upload for some reason so I don't have pics available at the moment. Any help would be greatly appreciated.

[Redline novdog]

I am confused at first you say the lug studs with the rotors are to long, then later you say even if you had the right thread they would not be deep enough?
I do know you can buy wheel studs in different lenghts & diameters,screw in press in.etc...
I put longer ones on my Nova with open ended lug nuts to pass tech

[Malamute]

Sorry, I meant the lug nuts wouldn't be deep enough. The open lugs was my thought as well. I can pull the rotor easily and go get the right lugs for the time being. I just wasn't expecting a different thread and double the length, caught me off guard.

Thanks.

[Redline novdog]

If they sold you the right kit. It sure isn't plug&play ! Sorry for the problems.but will help someone else including me when I get to do a brake swap.

[lolife99]

EDITED for correct lug size:
You should have a 6x5.5 bolt pattern hub with 7/16" lug studs.
I can see them being slightly longer.
I assume you have a bearing hub and a hat style rotor that slides over the lug studs?

[lolife99]

Pics would really help.
I can upload pics directly from my phone but you have to do them 1 pic per post.

[Malamute]

This is a 6 lug set up for my '69, it's not a hat style rotor.

Finally got pics to work, had a bad USB port.

[lolife99]

wow.
I'm not sure what lug studs they used but they are way to long.
I would change them or use a different rotor.
The studs knurl even sticks out the front side of the rotor!

[Malamute]

Thanks for the input, new studs it is. I honestly didn't even look at the studs before I started, it really caught me off guard.

I bought these off of the board a while back, they were used for a mock up before he went with a BB kit.

[lolife99]

The previous owner must have changed those studs.
I've never seen them that long before.

[Andy4639]

Originally Posted by lolife99

wow.
I'm not sure what lug studs they used but they are way to long.
I would change them or use a different rotor.
The studs knurl even sticks out the front side of the rotor!

He must of had them put in just to make it asey to install his mockup stuff. Dang them are long!

[lolife99]

I would price out 12 lug studs and compare it to new rotors at $129.
http://www.summitracing.com/parts/cl...MobileSwitchNo

Make sure the original holes weren't drilled oversize for the new longer studs.
May be easier/cheaper to get new rotors.

[Malamute]

I could ask him but it doesn't really matter now. They were still a good deal, I'll just put the same thread and length studs that I had on the drums and all will be good. They were on Cloud 9.

[Redline novdog]

Seeing the studs, those are racing oriented with the taper before the threads.That being the studs only.They do not belong on those hubs !

[lolife99]

Originally Posted by Redline novdog

Seeing the studs, those are racing oriented with the taper before the threads.That being the studs only.They do not belong on those hubs !

I agree.
Wonder if there was a stack of slide on spacers on them.
That's a bad idea too.

[picklito]

Originally Posted by lolife99

I agree.
Wonder if there was a stack of slide on spacers on them.
That's a bad idea too.

Spacers my thought, too.

It's a good idea to check, check, and re-check your lug nut torque after you change studs. They often settle in for quite a while. Then check them again. Did I mention that you should also check the lug nuts?

[Malamute]

The replacement studs were definitely cheaper on Summit. $17 for 10. I just hope the holes haven't been altered. I'm going to pop these out before I order them.

Thanks again for the assistance everyone.

[lolife99]

Were the studs 7/16" or 1/2"?
I just remembered my 6-lug rotors are 7/16" so they match the rear axles.

[Malamute]

Pretty sure they are 7/16. Everything I can find says that was stock in '69 and these were the stock drums. I'm surprised the truck stopped after seeing how melted and bad the shoes were. This was long overdue, I doubt the PO ever did anything to the brakes.

[Malamute]

A busy week at work and a pinched sciatic nerve kept me out of the garage this week. Pulled the rotors today and they are spot welded on the back side of the studs. No clue what, why or how. Unfortunately this wasn't mentioned when I bought them.

Looks like I'll be going with the rotors you linked Keith, thanks.

[nascarguy320]

Sorry to be off the subject but what center caps are those

[Malamute]

They were on the wheels when I bought the truck. I'm guessing early to mid 80's but someone that knows more than I do can chime in.

[lolife99]

The center caps are off of the 88-98 4x4 steel wheels.

[Malamute]

Originally Posted by lolife99

EDITED for correct lug size:
You should have a 6x5.5 bolt pattern hub with 7/16" lug studs.
I can see them being slightly longer.
I assume you have a bearing hub and a hat style rotor that slides over the lug studs?

Thanks, Keith.

The link you provided doesn't say what size the studs are. One of the comments states that he pressed out the 1/2" studs for a different size. I have to assume that these are correct for my application though wouldn't you think?

[lolife99]

Yes I think they are correct.
I think all the 6-lug rotors have 7/16" lug studs.
The rotors on my '69 came from performance online.com.
ECE sells them also.
I listed the CPP version from Summit a Racing because they seem to be the cheapest.
And Summit has better customer service that buying directly from CPP.