55.2-59 56 straight axle squarebody hubs

[regan56]

Hey...need some help here.

My original idea of getting a M2 IFS from Heidts just won't materialize fast enough financially for me to wait any longer. Ive picked up my original straight axle and springs for mounting under my original frame but ive already mounted a squarebody rear end and flipped springs in the rear. Im wanting the 5x5 chevy bolt pattern so how can i manage to get the front pattern to match the back pattern with disc brakes?

I looked at the hub assembly from a SB and the spindles of my 56 and they obviously wont fit onto the straight axle as the kingpins are very different lengths...but will the SB hubs fit over the spindle shaft of my 56? Or what else is available to me to make this setup happen?

Also..just to confuse the issue im needing to drop the front end. I see in LMC they have 2" lowering leaf springs for the front..anybody here know what those are like? Assume its just a flatter profile and less leafs to create the drop.

[57tailgater]

First of all, the SB hubs are NOT for king pins - they use ball joints at the top and bottom. Using the sb hubs (I am assuming you're wanting to swap to disc brakes) on your stock spindles would take some adapting, just like the aftermarket kits now available. Check places like Speedway, CPP, LMC, etc. to see what they offer - not sure if they have the 5x5 bolt pattern or not.

Yes the springs will have less leafs and be flatter. Do a search as there are people on here that have done that.

[mgchevyparts]

The normal bolt on 5 lug disc brake conversion for your straight axle uses 1970-78 Camaro rotors which are 5 on 4.75" However, Speedway carries those rotors in a 5 on 5" pattern so you're covered there.

[regan56]

Originally Posted by 57tailgater

First of all, the SB hubs are NOT for king pins - they use ball joints at the top and bottom.

i cant even believe i thought that would work..i knew the SB use ball joints... ive changed a few too..wow..unreal..#majorbrainfart

[57tailgater]

Originally Posted by regan56

i cant even believe i thought that would work..i knew the SB use ball joints... ive changed a few too..wow..unreal..#majorbrainfart

We've all been there! I think at one time I had wondered about it they could be modified to work so don't feel bad. Would be nice if someone would come up with a dropped spindle to fit the stock I beam and hubs but don't know if it's even possible.

[joedoh]

for your leafs, see if you have a local shop that does de-arching, they will have something like "spring and axle" in their name. the local shop may be cheaper than the aftermarket even with new bushings.

[regan56]

Originally Posted by mgchevyparts

The normal bolt on 5 lug disc brake conversion for your straight axle uses 1970-78 Camaro rotors which are 5 on 4.75" However, Speedway carries those rotors in a 5 on 5" pattern so you're covered there.

so i was diggin around on Speedway.com and found the drum to disc conversion kit and whatnot, but found teh kit came with the 5x4.75 pattern. i asked if they had the 5x5 pattern instead and heres teh response: "you inquired about part number 91031916 and availability with a 5 on 5 lug pattern. We apologize but we do not offer a similar kit with that lug pattern. Speedway uses readily available parts to keep the price as low as possible. "

i find it tough to believe that im one of the ONLY guys to ask about a conversion for my 55-59 chevy to disc brakes and a pretty std chevy truck bolt pattern..using my stock spindles

so the following is the convo:


Regan:
So can i swap in that pattern..do you have that disc with that pattern thats not in a kit? Standalone that i can swap in in place of the 5x4.75?

Speedway:
That we do not have or we would offer a kit with the 5 on 5. You may want to check with Brake Tech Solutions or ECI” Brake for availability of a kit with that lug pattern.

Regan:
Ok..fair enough. Thx for your help.

Regan:
last question.. say i do buy this kit, and source a set of discs with the 5on5 pattern im looking for which wont be too difficult since every 2wd 1/2ton chevy truck in the 70s thru 80s came with that pattern,, with the bearings that come with this kit, will they fit?

Speedway:
Doubtful and the first obstacle would be the rotor diameter to match up with the caliper placement. Second would be where the bearings placed the rotor as far as inward or outward from the spindle. We have thought about casting a special rotor for your needs but so far haven’t had enough interest. Let me know if you come up with an 11” rotor and I can present it to the engineers for advisement.


now im stuck...

[regan56]

so now im thinking..

should i just buy this kit and get them re-drilled to a 5x5 pattern? this would mean every time i replace my front brake rotors id need to get this done but, that not that often i suppose

or

is it easier to get my rears drilled to a 5x4.75 or swap out my axles? id rather NOT do this as i have my wheel thoughts kinda set (squarebody rallyes)

[mgchevyparts]

They list the rotor with the 5 on 5 pattern, it just doesn't come in the kit. You're going to have to buy each separately apparently.
Trust me, I know the kit (I make and sell disc kits for a living just not trucks) the 1970-78 Camaro rotor is listed on their site with a 5 on 5 pattern.
I would buy the rotors first to make certain you get them, the kit with 5 on 4.75 is available from anyone.

Don't try redrilling a rotor, normally no space and even if there is it'll crack

[mgchevyparts]

This is the kit, #91031916 $269.99

These are the rotors you want in 5 on 5 #91031064 $49.95ea
https://www.speedwaymotors.com/1973-...Inch,1969.html

Same rotor that's used in the kit but different bolt pattern for their circle track racers
With part numbers in hand I guess it's worth a try to see if they would change rotors but I wouldn't hold my breath.

[regan56]

Originally Posted by mgchevyparts

This is the kit, #91031916 $269.99

These are the rotors you want in 5 on 5 #91031064 $49.95ea
https://www.speedwaymotors.com/1973-...Inch,1969.html

Same rotor that's used in the kit but different bolt pattern for their circle track racers
With part numbers in hand I guess it's worth a try to see if they would change rotors but I wouldn't hold my breath.

Lol..right on mgchevyparts!

Why would the guy tell me he dont have it? Doesn't he want a sale?

As i stared at that kit i realized its not a power brakes kit which would explain why its so reasonably priced compared to other kits i found that were PB with the master cylinder and booster included. I did find a kit from Classic Industries for my truck with the 5on5 and PB for $949USD but i haven't pulled the trigger yet

[mr48chev]

That speedway rotor is intended for dirt track use so there may be legal issues if you use it on the street and it fails. That would be up to you

There is a kit for 180 that has the brackets and bearing adapter but you still need the rotors and calipers Scroll down the page. http://ecihotrodbrakes.com/early_che...nversions.html

Personally if I had to have disk on the I beam I'd just go with that speedway kit or a similar one and run the 5 on 4-3/4 wheels on the front and carry a dual pattern spare.

You can swap 50/54 Pontiac drums and backing plates onto 47/59 Chevy 3100 spindles reasonably simply as they use the same wheel bearings. That is if you aren't bent on having disk brakes on the I beam.

[mgchevyparts]

Originally Posted by mr48chev

That speedway rotor is intended for dirt track use so there may be legal issues if you use it on the street and it fails. That would be up to you

There is a kit for 180 that has the brackets and bearing adapter but you still need the rotors and calipers Scroll down the page. http://ecihotrodbrakes.com/early_che...nversions.html

Personally if I had to have disk on the I beam I'd just go with that speedway kit or a similar one and run the 5 on 4-3/4 wheels on the front and carry a dual pattern spare.

You can swap 50/54 Pontiac drums and backing plates onto 47/59 Chevy 3100 spindles reasonably simply as they use the same wheel bearings. That is if you aren't bent on having disk brakes on the I beam.

Those rotors are stronger then OEM, they have 5/8 studs instead of 7/16"
The only correct way to change bolt pattern, is the way these are made drilled from the factory. No liability what so ever.

[regan56]

Originally Posted by mgchevyparts

Those rotors are stronger then OEM, they have 5/8 studs instead of 7/16"
The only correct way to change bolt pattern, is the way these are made drilled from the factory. No liability what so ever.

so different lug nuts then eh..

[mr48chev]

Yes because they are intended for race cars with race wheels that use 5/8 lug bolts. and lug nuts that the racing organizations require.

What I was saying though is that they are not approved for street use by the DOT of the US or Canada. That simply means if you get in a wreck and they thoroughly inspect your truck you are up a s--- creek with no paddle The "oh they are stronger " nonsense doesn't really fly then.

You might want to check your wheels with a 5/8 bolt to see if one would even go though the lug bolt hole.

[mgchevyparts]

Originally Posted by mr48chev

Yes because they are intended for race cars with race wheels that use 5/8 lug bolts. and lug nuts that the racing organizations require.

What I was saying though is that they are not approved for street use by the DOT of the US or Canada. That simply means if you get in a wreck and they thoroughly inspect your truck you are up a s--- creek with no paddle The "oh they are stronger " nonsense doesn't really fly then.

You might want to check your wheels with a 5/8 bolt to see if one would even go though the lug bolt hole.

DOT only regulates rotor thickness in big trucks not our trucks or cars.

Original 5 on 5 used 1/2" studs the 5/8" should fit but that's a good idea to check that first.

https://legalbeagle.com/6076515-dot-...uirements.html

[regan56]

Good comments on the lugs sizes..really.

Just a question here if things go south. Is it possible to just swap out my rear axles.in favour of an axle with 5x4.75 in my SB rear end?

Or just move to a 6 lug pattern...

[mr48chev]

I don't know of one that will swap. You might be able to have the axles and drums redrilled for the 5 on 4-3/4 pattern but that might cost as much as using a car axle with the right bolt pattern.

[regan56]

Ya..i thought about that too.

I will likely spring for the 5x5 kit from Classic Parts..its pricey but probly by the time i buy some hubs that might not even work ill be close to the same cost..even if i swapped lug patterns now id have to buy new rear drums and wheels so...

I appreciate the discussion fellas.

[mgchevyparts]

Originally Posted by regan56

Good comments on the lugs sizes..really.

Just a question here if things go south. Is it possible to just swap out my rear axles.in favour of an axle with 5x4.75 in my SB rear end?

Or just move to a 6 lug pattern...

We commonly install complete rear ends from 1955-57 Chevy car, width is perfect about an inch smaller and you just reposition and weld the spring perches to match the stock leaf springs. Yours is a 55-59 truck, right

[regan56]

Originally Posted by mgchevyparts

We commonly install complete rear ends from 1955-57 Chevy car, width is perfect about an inch smaller and you just reposition and weld the spring perches to match the stock leaf springs. Yours is a 55-59 truck, right

Thats right. 56 GMC. Shortbed Step so i wanted to keep with a truck pattern an the rear end is from a 75 truck with the springs from the same. I had to reposition the hangers to fit the spring length. Took out the overload leaf and flipped the axle.

[mgchevyparts]

You can put that kit together for a lot less then Classic's outrageous price. You can get the bracket/bearing adaptor kit for around $110, then buy the rotors for $100 from Speedway, then buy 69-72 Chevelle calipers from cheapest you can find, hoses bearings etc, you'll be in it around $350. Then purchase booster kit separately around $300. Of course being in Canada adds some drama to this.

[regan56]

Originally Posted by mgchevyparts

You can put that kit together for a lot less then Classic's outrageous price. You can get the bracket/bearing adaptor kit for around $110, then buy the rotors for $100 from Speedway, then buy 69-72 Chevelle calipers from cheapest you can find, hoses bearings etc, you'll be in it around $350. Then purchase booster kit separately around $300. Of course being in Canada adds some drama to this.

I could yes....if i knew i could find the rotors i wanted and that fits my stock '56 spindle.The 5/8 stud might be a deal killer as i dont think those will fit the slots in my rims. I didnt have a 5/8 bolt on hand but a 1/2" is pretty close to using up all the 'extra' room there is.

[mgchevyparts]

Originally Posted by regan56

I could yes....if i knew i could find the rotors i wanted and that fits my stock '56 spindle.The 5/8 stud might be a deal killer as i dont think those will fit the slots in my rims. I didnt have a 5/8 bolt on hand but a 1/2" is pretty close to using up all the 'extra' room there is.

All kits use the 70-78 Camaro rotor. Speedway has them drilled in different patterns. The rotor does not fit your spindles directly, an inner bearing adaptor has to be used. It's either the 70-78 Camaro rotors or the 6 lug kit that re-uses your drum hubs, that's all that is available for your stock spindles.
You might find a 1/2" lug stud with a knurl that could be used to substitute the 5/8 studs but you won't know that until you have the rotors in hand and measure the existing hole size. If you want 5 on 5 that's what your choices are.
If you're using alum wheels you can redrill the holes for the larger size, should be done on a vertical mill

[regan56]

Originally Posted by mgchevyparts

All kits use the 70-78 Camaro rotor. Speedway has them drilled in different patterns. The rotor does not fit your spindles directly, an inner bearing adaptor has to be used. It's either the 70-78 Camaro rotors or the 6 lug kit that re-uses your drum hubs, that's all that is available for your stock spindles.
You might find a 1/2" lug stud with a knurl that could be used to substitute the 5/8 studs but you won't know that until you have the rotors in hand and measure the existing hole size. If you want 5 on 5 that's what your choices are.
If you're using alum wheels you can redrill the holes for the larger size, should be done on a vertical mill

I do want the 5on5...i guess the only things I'm not sure of is the bearings and the lugs..the rest i could piece together with no double guessing myself.

The bearings..This is probably the biggest concern i have.