Pretty ticked right now...Rally wheels

[Stoney]

I've never seen it before either. Those wheels turned out nice.
The color shade looks perfect.

[SCOTI]

Originally Posted by f.monroe

Jeff, You have to be different dont you. J/K.
I have never seen one like the second one pictured. Just like Tx Firefighter , all of th rallys I have ever seen have looked like the first one pictured. I do remember seeing a Chrysler big Car with a factory wheel that looks identical to a GM truck Rally . I do not know what BP they used on the big car line but I have seen Rally wheels on them so maybe a 5"bp. Some even had a chromed center and painted rim. I wonder if that second pictured wheel is a GM wheel at all. I am also curious about the wheel dimensions.
Frank

Chrysler did make a similar wheel now that you mention it. I was wondering if they're from late model cop cars or something & made different vs. the early 73-87 6.5" van & 8" truck ralleys.

[68longhorn]

i'm pretty sure all of mine loke like the second. strange

[f.monroe]

Quick search on ebay turned up these pics.
First one is a 72 Newport and the second is a 77 New Yorker. The wheels are definitely GM Rally style an the center caps resemble the early GM centers as well. Only diff is that these wheels look to be 6.5 or 7 inches wide and not 8's.
Frank

[lolife99]

All of mine have been like Picture #2.
I've never seen the version in Picture #1.

Most of the wheels, with the center cap holes that were not tapped,... were factory spares.
I wonder if it's a regional thing.

[bigblock73]

Ok, more info

All rims are 9" wide actual...I measured them. I just call them 8" like everyone else.

Stampings on the wheels are as follows...

wheel 1
XAJ 7/28 mfr date 1984 41

wheels 2-4 (round hole)
XAJ 6/16 mfr date 1984 41
OK 3/31 mrf date 1910 40
BM 9/26 mfr date 1910 40

These are def all GM wheels by looking at the stampings and location.

What does the first set of letter indicate, and what do the last two sets of numbers indicate...anyone know?

I am very surprised most of you have seen/used the round hole wheels on various trucks with no problems, my '75 can't be a 1 of 1.

Really bummed right now, and if I machine the other 3 out...it's gonna bug me I have a mismatched wheel, despite not even being able to see it with a center cap on...lol. I need help, I know.

[bigblock73]

Originally Posted by lolife99

All of mine have been like Picture #2.
I've never seen the version in Picture #1.

Most of the wheels, with the center cap holes that were not tapped,... were factory spares.
I wonder if it's a regional thing.

I KNOW one of these was a spare off the 90 Suburban I parted out..just don't know which one..lol!

[bigblock73]

Frank, do you have a 70's truck right now with Rally's on it? If so, can you take a close look to confirm what type of center you have?

I am starting to wonder if GM changed designs at some point, say the 80's sometime...or perhaps in 88. Perhaps do to brake component and/or axle redesign or size changes.

I think a couple of these might be off the 90 'burb the more I think about it.

[f.monroe]

Here is what I found.
A couple sets of 15x7 Rallys ...all like pic1 with the smooth round hole.

At least ten 15x8 Rallys including the ones on the original owner 77 Big Block truck I have and they are all smooth round hole.

I have a set of 6.5 Van Rallys and they are all smooth round centers.

My 15x10 pair of aftermarket Rallys I think are smooth centered also .

I have ONE single wheel like the one in pic 2. It has 1984 stamped in the outer wheel lip and it is a 15x8 wheel with the irregular shaped center. Never noticed that before.

It does appear that the early rallys I have are all smooth round centers.

Frank

[bigblock73]

So the 77 BB truck you have will accept a smooth center hole, but my 75 BB will not...doesn't make any sense to me.

I could see maybe not fitting on the front due to aftermarket/replacement rotors...but the back doesn't fit either.

[1LowToy]

I have a set of the mopar wheels on my utility trailer. As far as I know all the mopars are 5x4.5" pattern. Could the odd wheels you have be made for the latter model C-10s with the light duty rotors (1.00" thickness) I have a 1.0 rotor and a 85 model rear end handy I can measure it tomorrow.

I'm coming across a freeby (73 C-10) truck soon and it for sure has the 5x4.75" wheels. I'm hoping it's a low greared posi since it's an old US Forestry truck. They loved posi tracts.

[rwhit57]

Originally Posted by 1LowToy

I have a set of the mopar wheels on my utility trailer. As far as I know all the mopars are 5x4.5" pattern. Could the odd wheels you have be made for the latter model C-10s with the light duty rotors (1.00" thickness) I have a 1.0 rotor and a 85 model rear end handy I can measure it tomorrow.

I'm coming across a freeby (73 C-10) truck soon and it for sure has the 5x4.75" wheels. I'm hoping it's a low greared posi since it's an old US Forestry truck. They loved posi tracts.

I have never heard of a 5 lug Chevy truck with anything other than 5X5"


The codes are just like the codes on the GM car Rallyes, they designate the wheel size and what it goes on, but have never seen the truck codes deciphered.

Now I have to go home and look at all my rallye wheels.

[lolife99]

Jeff,... Have you tried mounting them on your yellow truck?
I would compare rotor hubs and rear axle hubs between your two trucks.
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[bigblock73]

Originally Posted by lolife99

Jeff,... Have you tried mounting them on your yellow truck?
I would compare rotor hubs and rear axle hubs between your two trucks.
Posted via Mobile Device

I am going to try and find time to do that today....and let me tell you, if they fit, I will be completely stumped.

I would LOVE to know why the different design in wheels though.

[lolife99]

Originally Posted by bigblock73

I am going to try and find time to do that today....and let me tell you, if they fit, I will be completely stumped.

I would LOVE to know why the different design in wheels though.

I bet GM used different wheel suppliers.
73-87 (or 91 for 2wd burbs) is a long time to supply wheels.
Does your '75 have original rotors or replacements?
(that might explain the front,... but the rear should fit)

[80SPORT]

The hollander manual lists BK,BM,CK,XAJ as 15 x 8 truck wheels...all direct interchange.

My Chevy OEM parts book for 79 to 82 lists BM,BK andCK as 15x8 C10 wheel codes.

I suspect the XAJ code is for the newer wheel in the 73-87/91 series.

There are a lot of wheels out there so it is always a good idea to test fit on your truck before painting/powder coating/mounting tires.

[MadManAndrew]

Originally Posted by 80SPORT

There are a lot of wheels out there so it is always a good idea to test fit on your truck before painting/powder coating/mounting tires.

Also need to make sure you have four matching wheels too! Lol. No offense to OP, but I just can't imagine missing that myself, lol.
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[bigblock73]

Originally Posted by MadManAndrew

Also need to make sure you have four matching wheels too! Lol. No offense to OP, but I just can't imagine missing that myself, lol.
Posted via Mobile Device

They will match when the cap is on.

Like MOST of us on this forum, we all thought there was only one style to these wheels.

It's easy to sit back and judge, especially when you are perfect.

I am not.

[MadManAndrew]

I didn't mean to strike a nerve there man, sorry. I'm not trying to say I'm perfect and definitely not trying to insult you or anything. Just hoping everybody learns to be a little more attentive with our purchases from this.
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[bigblock73]

Originally Posted by 80SPORT

The hollander manual lists BK,BM,CK,XAJ as 15 x 8 truck wheels...all direct interchange.

My Chevy OEM parts book for 79 to 82 lists BM,BK andCK as 15x8 C10 wheel codes.

I suspect the XAJ code is for the newer wheel in the 73-87/91 series.

Well obviously, they aren't all a direct interchange as I have just found out..for some strange reason. Thank you for the info, much appreciated.

[msgross]

Just to confuse you even more... here is my 4x4 rally wheel... looks like it's a morph of the two options... smooth center with raised pads for the lugnuts... 6 lug of course

[1LowToy]

I just got in from the daily chores but I found time to measure the 84 rotors. As far as I could tell the came out to be about 3.165" in diameter. I hope that my caliper was reaching all the way around. Hope this helps I have my truck up in the air right now and I'll measure the 1980 original spare and see what it measures in the morning.

[bigblock73]

1lowtoy

The rotors on my '75 measure 3.06, or 3 1/8"...and the diameter of the center hole on the "round" wheels is roughtly 3 1/6"...I cannot get a caliper in there to measure, so that is a careful tape measure dimension. With your provided dimension, these wheels wouldnt fit your truck either.

[bigblock73]

More useless info for you guys, Mikes (msgross) 6 lug wheels have 10 slots, the C10 5 luggers have 16...lol. How many ppl knew that without looking?

Thanks for the pic Mike, and additional confusion...lol.

I didn't make it out to try the wheels on my 73...had a busy day, will try to get to it tomorrow.

[SCOTI]

Originally Posted by bigblock73

More useless info for you guys, Mikes (msgross) 6 lug wheels have 10 slots, the C10 5 luggers have 16...lol. How many ppl knew that without looking?

Thanks for the pic Mike, and additional confusion...lol.

I didn't make it out to try the wheels on my 73...had a busy day, will try to get to it tomorrow.

I knew that bit of useless info