Wheel/Tire Opinion

[Mlcdc1]

I‘d like to put a wider tire on my 1977 GMC C15 and looking for recommendations/suggestions. I’m currently running 235/75 R15 on factory steel wheels. I think I’d like to keep the appearance close to original and would welcome recommendations for a good/reliable source for wheels and tire size options. Thanks in advance for all your input.

 

[Grit dog]

Beautiful truck!
US Wheel steelies. 15x8 or 10 or 16x8 or 10.
May be able to get other diameters as well in the smaller bolt patterns like half tons.

 

[Redfish]

I‘d like to put a wider tire on my 1977 GMC C15 and looking for recommendations/suggestions. I’m currently running 235/75 R15 on factory steel wheels. I think I’d like to keep the appearance close to original and would welcome recommendations for a good/reliable source for wheels and tire size options. Thanks in advance for all your input.

What exactly are you asking here? Are you looking for new wheels? Or just looking to get a wider tire? A tire that is wider but not taller?

I think you are asking for a wider tire that is close to the same height. If that is your question, it may help you to know what those numbers actually mean.
235=235 millimeters wide inflated
75 is a ratio or percent. The distance from the edge of the rim to the outside edge of the tire is 75% of 235mm.

Also, are you wanting to stay with the All-Terrain tire or a more street oriented tire?

 

[Mlcdc1]

I’m open to all suggestions. I leaning towards a street tread tire (BF Goodrich or Cobra?), a little wider and definitely not taller and a little shorter would do ok also. Thanks for the clarification on what the numbers mean.

 

[bucket]

A 255/70/15 would be a little wider, but not taller. It would fit the current rim ok too. They are available from the normal "white letter tire" makers that still exist.

 

[Redfish]

If you are going to keep your original wheels (and I encourage you to do that! They look great!) the 255/70R15 that @bucket recommended might be exactly what you need.

I will "argue" with bucket that the 255/70 is slightly taller than the 235/75...but we are talking a total of 4.5mm. That is 0.177165 inch! So honestly no difference in height.

If you are going to go with a street tire your next step wider would be a 275/60R15. Those would actually be slightly shorter than your 235/75 but would be pushing the width of your factory wheels.

I really think that the 255/70 that bucket recommended is going to be about right for your setup.

Beautiful truck by the way.

 

[bucket]

If you are going to keep your original wheels (and I encourage you to do that! They look great!) the 255/70R15 that @bucket recommended might be exactly what you need.

I will "argue" with bucket that the 255/70 is slightly taller than the 235/75...but we are talking a total of 4.5mm. That is 0.177165 inch! So honestly no difference in height.

If you are going to go with a street tire your next step wider would be a 275/60R15. Those would actually be slightly shorter than your 235/75 but would be pushing the width of your factory wheels.

I really think that the 255/70 that bucket recommended is going to be about right for your setup.

Beautiful truck by the way.

Yeah, I never worry about exact dimensions based on a tire "size" because the real world measurements are all over the place. Diameters can vary by as much as a half inch, just between tire brand and model. Widths can vary by a full inch.

 

[mcarlo86]

A 255/70/15 would be a little wider, but not taller. It would fit the current rim ok too. They are available from the normal "white letter tire" makers that still exist.

This is the size I put on my ‘68 C10. I’m very happy with them. Got Mastercraft Avenger G/T tires in white letter. Similar to Cooper Cobras or BFG T/A’s but a little less money.

 

[Finkaire]

15x8 rallies with 275/60/15’s all around, Coopers.
Those wheels with all terrains would definitely look good with the 70’s

 

[Ricko1966]

Yeah, I never worry about exact dimensions based on a tire "size" because the real world measurements are all over the place. Diameters can vary by as much as a half inch, just between tire brand and model. Widths can vary by a full inch.

On my GTO I always noticed the back tires were always shorter than the fronts real soon.

 

[Rusty Nail]

255/70

https://tiresize.com/calculator/https://tiresize.com/calculator/

Plus!
Those wheels are madd heavy yo. Anything the same size aluminum would make your truck go faster and get better gas mileage..and handling would improve.

 

[FireTruck1984]

Yes, as suggested by the other guys, 255/70R15 is a good fit and great look… I’m running that setup on my C1500. Here’s a pic

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[Ricko1966]

255/70

https://tiresize.com/calculator/https://tiresize.com/calculator/

Plus!
Those wheels are madd heavy yo. Anything the same size aluminum would make your truck go faster and get better gas mileage..and handling would improve.

Now that's just crazy talk. None of that matters on trucks.

 

[Radiohead]

This is always great fun to play with

Tire Height Calculator

Easy to use tire height calculator. Use our tire height calculator to calculate the diameter of metric tire sizes. Browse all sizes with our tire height chart.

tiresize.com

 

[Mlcdc1]

Pick up a set of old school rally’s 15x7 and the tire shop recommended going with a 255/60 R15.
opinions??