275/60/15 at all 4 corners: lowering experts, please come in - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Luke87gt · 04-18-2024, 01:08 AM

Hi guys,

My ‘69 c10 is getting 275/60/15 at all 4 corners on 15x8 4.0” BS truck rallys.

I’m debating whether to do a 2/4 or a 3/5 drop.

Will either of these drops present any problems for me with the wheel combination above?

Thanks

Luke

Marc33 · 04-18-2024, 08:45 AM

following....

67C10Step · 04-18-2024, 09:11 AM

OK, not a lowering expert, but I have a similar setup to what you are describing. My truck is a 2.5/4 static drop with 8" rally wheels. I went with 255/70-15 at the time to better fill up the fender wells.

I could easily add another 20mm of tread width and drop the front or rear another inch without any issues.

cj847 · 04-18-2024, 11:44 AM

I am not an expert but here is my story.

1967 with 2.5 spindle drop 4" rear. 235/75/15. When I go over a big dip at speed the front tire will contact the inner fender.

My tires are smaller than 67C10step yet I have a problem and he doesn't. All that to say, I bet your plan will work. I just recommend that while you have the springs out, check the clearance with the truck on the bump stops. Then adjust things to make it work.

67C10Step · 04-18-2024, 12:01 PM

Quote:

Originally Posted by cj847

I am not an expert but here is my story.

1967 with 2.5 spindle drop 4" rear. 235/75/15. When I go over a big dip at speed the front tire will contact the inner fender.

My tires are smaller than 67C10step yet I have a problem and he doesn't. All that to say, I bet your plan will work. I just recommend that while you have the springs out, check the clearance with the truck on the bump stops. Then adjust things to make it work.

Interesting. The sidewall height on our two tire selections should not be very much different. When you did the drop spindle install did you replace the springs? Just thinking if you re-used the old springs they may have enough sag to give you more drop than I got out of mine. I replaced my front springs with stock height but now sort of wish I'd gone with a 1" drop spring.

CG · 04-18-2024, 01:09 PM

Here is a thread for 15 inch wheels only. I believe there are a lot of trucks in here that have the combo you are asking about.

https://67-72chevytrucks.com/vboard/...t=15+inch+only

cj847 · 04-18-2024, 08:37 PM

Quote:

Originally Posted by 67C10Step

Interesting. The sidewall height on our two tire selections should not be very much different. When you did the drop spindle install did you replace the springs? Just thinking if you re-used the old springs they may have enough sag to give you more drop than I got out of mine. I replaced my front springs with stock height but now sort of wish I'd gone with a 1" drop spring.

The drop was installed by the previous owner. And the springs are definitely old and tired.

The thing that bothers me is regardless of what spring, if it ever hits hard enough to reach the bump stop it is going the interfere.

67C10Step · 04-18-2024, 08:55 PM

Quote:

Originally Posted by cj847

The drop was installed by the previous owner. And the springs are definitely old and tired.

The thing that bothers me is regardless of what spring, if it ever hits hard enough to reach the bump stop it is going the interfere.

Dang man! You need to slow down! Just kidding. I’ve driven mine over 3000 miles since doing the suspension and getting it on the road and I’ve never even felt like I was close to hitting the bump stops up front.

**mm1077** · 04-18-2024, 09:41 PM

Quote:

Originally Posted by Luke87gt

Hi guys,

My ‘69 c10 is getting 275/60/15 at all 4 corners on 15x8 4.0” BS truck rallys.

I’m debating whether to do a 2/4 or a 3/5 drop.

Will either of these drops present any problems for me with the wheel combination above?

Thanks

Luke

This is my truck with 2/4 spring drop. 15x8 rallies w 275/60 on all 4. Daily drove it for a year with this setup -never an issue and our roads can get pretty rough around here. I just went to steelies and caps for the look I wanted.
Posted via Mobile Device

Luke87gt · 04-18-2024, 10:25 PM

Quote:

Originally Posted by mm1077

This is my truck with 2/4 spring drop. 15x8 rallies w 275/60 on all 4. Daily drove it for a year with this setup -never an issue and our roads can get pretty rough around here. I just went to steelies and caps for the look I wanted.
Posted via Mobile Device

Very nice! What drop kit is that?

**MikeB** · 04-19-2024, 12:14 PM

FWIW, 255-70x15 tires on 8" rally wheels from a square body truck barely rubbed the bolts holding my inner fenders to the outers. It only happened on bumpy roads while turning. I fixed it by replacing the hex head bolts with button head bolts. My truck has somewhere around a 2" drop at the front.

However, 275-60x15 tires are shorter than mine, so you may not have a problem, depending on how low you go.

**mm1077** · 04-19-2024, 12:57 PM

Quote:

Originally Posted by Luke87gt

Very nice! What drop kit is that?

Western chassis parts
Posted via Mobile Device

Luke87gt · 04-19-2024, 06:41 PM

Quote:

Originally Posted by mm1077

Western chassis parts
Posted via Mobile Device

With a 2inch spring drop, can you align to spec ?

**MikeB** · 04-20-2024, 05:06 PM

That's a real beauty with a very nice stance.

kaycee · 04-20-2024, 09:29 PM

275/60/15 on 15 x8 all 4 corners 2.5" front 4 " rear static drop no issues on rubbing . Rear tires wear out twice as fast as fronts

67swb72klb · 04-20-2024, 10:26 PM

Never had an issue with mine not really sure on the drop on it though..

HalfBrit · 04-21-2024, 01:02 AM

I ran 275/60's for many years with a 2.5" spindle + 1" drop spring in the front. The rear was a 4" drop spring. This pic is that same drop with slightly smaller overall diameter 255/50-17's.

**MikeB** · 04-21-2024, 10:50 AM

Earlier I wrote: "255-70x15 tires on 8" rally wheels from a square body truck barely rubbed the bolts holding my inner fenders to the outers."

My truck does have 85 spindles. I wonder if they position the wheel outboard just a little further? It's not much, because button head bolts fixed the problem! Tires are Cooper Cobras, which may be a shade wider or taller than BFG Radial T/As.

Luke87gt · 04-22-2024, 12:18 AM

Quote:

Originally Posted by MikeB

Earlier I wrote: "255-70x15 tires on 8" rally wheels from a square body truck barely rubbed the bolts holding my inner fenders to the outers."

My truck does have 85 spindles. I wonder if they position the wheel outboard just a little further? It's not much, because button head bolts fixed the problem! Tires are Cooper Cobras, which may be a shade wider or taller than BFG Radial T/As.

Cooper Cobras are generally a tad narrower than BFG T/As from my experience

04-18-2024, 01:08 AM	#1
Luke87gt Registered User Join Date: Feb 2024 Location: Pleasanton CA Posts: 232	275/60/15 at all 4 corners: lowering experts, please come in Hi guys, My ‘69 c10 is getting 275/60/15 at all 4 corners on 15x8 4.0” BS truck rallys. I’m debating whether to do a 2/4 or a 3/5 drop. Will either of these drops present any problems for me with the wheel combination above? Thanks Luke __________________ 1969 C10 Shortbed

04-18-2024, 08:45 AM	#2
Marc33 Registered User Join Date: Feb 2010 Location: San Marcos, Ca Posts: 109	Re: 275/60/15 at all 4 corners: lowering experts, please come in following.... __________________ Current stable: 1970 K5 Blazer 4x4 1972 K5 Blazer 4x4 SOLD: 1971 GMC Sierra Grande 2500 2wd 1972 Chevrolet K5 Blazer 1966 Chevrolet C20 1972 Chevy Suburban 4x4 1500 1956 Chevy 150 2 door post 1956 Chevy 2 door post bel air 1968 Chevrolet C20 1958 Ford Thunderbird 1968 4x4 Suburban 1/2 ton

04-18-2024, 09:11 AM	#3
67C10Step Registered User Join Date: Jul 2019 Location: Beebe, AR Posts: 2,475	Re: 275/60/15 at all 4 corners: lowering experts, please come in OK, not a lowering expert, but I have a similar setup to what you are describing. My truck is a 2.5/4 static drop with 8" rally wheels. I went with 255/70-15 at the time to better fill up the fender wells. I could easily add another 20mm of tread width and drop the front or rear another inch without any issues. Attached Images __________________ 1967 C10 1980 Jeep CJ5 2020 Toyota 4Runner 2024 Toyota Tundra

04-18-2024, 11:44 AM	#4
cj847 Registered User Join Date: Sep 2016 Location: Ozark, MO Posts: 573	Re: 275/60/15 at all 4 corners: lowering experts, please come in I am not an expert but here is my story. 1967 with 2.5 spindle drop 4" rear. 235/75/15. When I go over a big dip at speed the front tire will contact the inner fender. My tires are smaller than 67C10step yet I have a problem and he doesn't. All that to say, I bet your plan will work. I just recommend that while you have the springs out, check the clearance with the truck on the bump stops. Then adjust things to make it work.

04-18-2024, 01:09 PM	#6
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,035	Re: 275/60/15 at all 4 corners: lowering experts, please come in Here is a thread for 15 inch wheels only. I believe there are a lot of trucks in here that have the combo you are asking about. https://67-72chevytrucks.com/vboard/...t=15+inch+only __________________ … … … … … … … … ... … … … … … … … … … … …

04-19-2024, 12:14 PM	#11
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,599	Re: 275/60/15 at all 4 corners: lowering experts, please come in FWIW, 255-70x15 tires on 8" rally wheels from a square body truck barely rubbed the bolts holding my inner fenders to the outers. It only happened on bumpy roads while turning. I fixed it by replacing the hex head bolts with button head bolts. My truck has somewhere around a 2" drop at the front. However, 275-60x15 tires are shorter than mine, so you may not have a problem, depending on how low you go. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

04-20-2024, 05:06 PM	#14
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,599	Re: 275/60/15 at all 4 corners: lowering experts, please come in That's a real beauty with a very nice stance. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!

04-20-2024, 09:29 PM	#15
kaycee Registered User Join Date: Jan 2000 Location: Wyoming USA Posts: 2,453	Re: 275/60/15 at all 4 corners: lowering experts, please come in 275/60/15 on 15 x8 all 4 corners 2.5" front 4 " rear static drop no issues on rubbing . Rear tires wear out twice as fast as fronts Attached Images __________________ 2001 Silverado K-1500 2005 FXDWG stage3 69 CHEVY Short/Step 327/4L60 373 posi 63 IMPALA 327/4L60 Last edited by kaycee; 04-20-2024 at 09:31 PM. Reason: brain tumor

04-20-2024, 10:26 PM	#16
67swb72klb Registered User Join Date: Dec 2010 Location: livingston co.mi Posts: 2,471	Re: 275/60/15 at all 4 corners: lowering experts, please come in Never had an issue with mine not really sure on the drop on it though.. Attached Images __________________ California 65 GTO---Texas 64 burb 283 ---Oklahoma 67 CST SWB BBW wood bed 327 2004r---New Mexico 72 k10 350 350 auto---Georga 72 short step project

04-21-2024, 01:02 AM	#17
HalfBrit Registered User Join Date: Feb 2021 Location: Kernersville, NC Posts: 98	Re: 275/60/15 at all 4 corners: lowering experts, please come in I ran 275/60's for many years with a 2.5" spindle + 1" drop spring in the front. The rear was a 4" drop spring. This pic is that same drop with slightly smaller overall diameter 255/50-17's. Attached Images

04-21-2024, 10:50 AM	#18
MikeB Senior Member Join Date: Jul 2000 Location: North Texas Posts: 3,599	Re: 275/60/15 at all 4 corners: lowering experts, please come in Earlier I wrote: "255-70x15 tires on 8" rally wheels from a square body truck barely rubbed the bolts holding my inner fenders to the outers." My truck does have 85 spindles. I wonder if they position the wheel outboard just a little further? It's not much, because button head bolts fixed the problem! Tires are Cooper Cobras, which may be a shade wider or taller than BFG Radial T/As. __________________ Mike 1969 C10 LWB -- owned for 35 years. 350/TH350, 3.08 posi, 1st Gen Vintage Air, recent AAW wiring harness, 5-lug conversion, 1985 spindles and brakes. 1982 C10 SWB -- sold 1981 C10 Silverado LWB -- sold, but wish I still had it! 1969 C10 (not the current one) that I bought in the early 1980s. Paid $1200; sold for $1500 a few years later. Just a hint at the appreciation that was coming. Retired as a factory automation products salesman. Worked part-time over the years for an engine builder and a classic car repair shop. Member here for 24 years! This is the very first car/truck Internet forum I joined. I still used a dial-up modem back then!



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