New Wheels Advice Please

[samkost]

I have a line on purchasing some Corvette Ralley wheels for my 72' C10 and could use some of your advice and opinions.

Will a 15X8" 4.25 back spacing with a 3.75 offset wheel be correct for my truck?
Will these bring each tire/wheel outward a bit in their respective wheel well compared to the original truck ralleys? I would be happy if they did.

I just want to confirm that these will mount up to my 72' correctly with the stock Disc Brakes/Rear Drums.


Thanks
Sam

[OARNGESI]

Same with and BS 295 50 15 245 60 15 tire 3/5 drop

[James the III]

Originally Posted by samkost

I have a line on purchasing some Corvette Ralley wheels for my 72' C10 and could use some of your advice and opinions.

Will a 15X8" 4.25 back spacing with a 3.75 offset wheel be correct for my truck?
Will these bring each tire/wheel outward a bit in their respective wheel well compared to the original truck ralleys? I would be happy if they did.

I just want to confirm that these will mount up to my 72' correctly with the stock Disc Brakes/Rear Drums.


Thanks
Sam

make sure these are the large car and truck 5 on 5 lug pattern not the 4.75" car /vette pattern

[rharris]

original truck rallys (assume the 73 and up) are 4" back spacing. So the wheel would be towards the inside 1/4" more with your vette rally's I have learned that a 1/4" from this wheel to that wheel can be different. I am going to use 4 1/4" backspacing steelies (72) with 275/60's - the front look really close without the tire. I will let you know how I make out. Good luck. If anything you may have to play around with front tire size. I think I said that right.....check out below link.
http://www.autoanything.com/wheels-r...el-backspacing

[samkost]

Originally Posted by James the III

make sure these are the large car and truck 5 on 5 lug pattern not the 4.75" car /vette pattern

Will do!
This is why I enjoy learning from this forum.
What would be the tallest and widest tire size to mount for filling up the wheel well?
I was thinking 285/60/R15 ?

Thanks James

[samkost]

Originally Posted by rharris

original truck rallys (assume the 73 and up) are 4" back spacing. So the wheel would be towards the inside 1/4" more with your vette rally's I have learned that a 1/4" from this wheel to that wheel can be different. I am going to use 4 1/4" backspacing steelies (72) with 275/60's - the front look really close without the tire. I will let you know how I make out. Good luck. If anything you may have to play around with front tire size. I think I said that right.....check out below link.
http://www.autoanything.com/wheels-r...el-backspacing

O.K. Great info here.
I'm learning to understand the formula relating to backspacing.
I currently have the original 15" wheels on my C10, so are they a 4" back space also?
Thanks rharris

[rharris]

those look to be 7", and I do believe the backspace is the same on the truck rally's at 4". I had 255/70/15's on my old 71 GMC. Height was very nice and width wasn't bad either.

[geezer#99]

Here's some info on backspacing/offsets in both metric and standard.
http://www.rimsntires.com/specspro.jsp

[samkost]

Thanks for the stance/tire photo of your GMC rharris.
I don't want to deviate too much.
My C10 has been lowered/leveled slightly with lower coils.
Currently running P235/75R/15's.
It think it needs some taller tires
My vision is to just fill up the wheel wells a bit more.
Trying to find a happy medium.
Thanks again,
Sam

[CC69Rat]

Originally Posted by samkost

Will do!
This is why I enjoy learning from this forum.
What would be the tallest and widest tire size to mount for filling up the wheel well?
I was thinking 285/60/R15 ?

Thanks James

Is the truck lowered at all? Stepside or Fleetside?

[samkost]

Thanks Geezer for the link.
CC69Rat, Yes, Fleetside and slight drop with coils.

[CC69Rat]

sorry about that, our posts hit about the same time.

To figure out your tire size and what you have now, vs how much bigger you want to go..


I'll use your example. 285/60/15

The first number of course is the width, but it's metric so let's convert that to inches first. 285 ÷ 25.4 = width in inches.

Then whatever that comes out to be (don't have a calculator at the.moment) multiply it by the aspect ratio. X .60

That will give you the height of the sidewalls. So, from the bottom of the wheel to the ground and from the top of the wheel to the top of the tire. We have two of those.. so, X2.

Then add your wheel diameter in inches.

285 ÷ 25.4 x .60 x 2 + 15

Just adjust your formula and you'll find a tire you're happy with. From an overall height perspective it can make or break the looks of your truck, absolutely. I usually try to find a tire the rear sidewalls are just a little more than the front but not a lot. And likewise in my opinion it looks kinda off if the sidewalls up front are bigger than the back, just so you can fit a wider tire under it. Hope this helps

[samkost]

Thanks Chad,
Some great info you have sent.
When I said I didn't want to deviate too much, there is alot to consider.
I definitelty don't want to throw off things like the speedo and of course its great comfortable coil spring/sway bar ride.
Many Thanks

[James the III]

I'd love to know if those thin chrome or maybe they are s/s trim rings work on the 70-80's truck ralleys..

As I'm not fond of the stock 3-4" wide ones on the truck and vette ralleys.. normally..





thin trim

[samkost]

James,
Is this what you are suggesting?
http://www.classicindustries.com/shop/search/?q=TR3125 or
http://www.classicindustries.com/pro...ts/tk3015.html
They expose the wheel slots a bit more?

[RGT]

Tire rack has a great data base of tire sizes and actual dimensions, I always find myself here when figuring which tires to run;
https://www.tirerack.com/tires/tires...omCompare1=yes

[rharris]

Samkost - below are 4.25" backspacing with 275/60/15. The tire is about a small fingers width to the upper control arm.

[randy500]

Originally Posted by rharris

Samkost - below are 4.25" backspacing with 275/60/15. The tire is about a small fingers width to the upper control arm.

Nice looking super...I like the way it sits, not lowered at all right? Seeing it in green and white makes me re-think changing mine to black and white.

[randy500]

Originally Posted by samkost

O.K. Great info here.
I'm learning to understand the formula relating to backspacing.
I currently have the original 15" wheels on my C10, so are they a 4" back space also?
Thanks rharris

Those are truck ralleys on your truck and I am almost certain 8" wide ones. Be careful on the purchase of vette ralleys, chevy never made them 8" wide with 5 x 5 truck bolt pattern.

[rharris]

Original suspension in picture. Planning on 2/3 drop.

[samkost]

Thanks guys for your replies.
Sam.