How big a tire . . . - The 1947 - Present Chevrolet & GMC Truck Message Board Network

palallin · 08-24-2002, 11:47 PM

What's the tallest tire one can run on a '69 K-10 withOUT lift or fender trimming?

TIA.

**JIMs70GMC** · 08-24-2002, 11:58 PM

probably 32X10.5/15 on an 8" rim. Anything taller or wider will catch the front lip of the fender well. (I'm running 31x12.50R15s on 10" wide rims w/ 4" backspacing and with a little flex the tires hit the front lip of the fenderwell while turning.) This is even with new bushing for the stock 3 leaf springs and new poly body mounts and ORDs 1/2" longer shackles. i'm actually think of adding ORDs 1" zero add-a-leafs. I like the look of the wide tires. They are good for the sand.

6869704X4 · 08-25-2002, 12:18 PM

Before I lifted my 70 K10 I was running 33x12.50/15s on 70s rallys. No hitting anywhere and did some serious wheeling with it.
Not sure of the backspacing on those factory wheels though. I can measure them for you if you want.

palallin · 08-25-2002, 11:57 PM

So, I should be OK with 31s on 7" rims?

71BBK10 · 08-26-2002, 09:24 AM

most definately, i have 31x10.50's on a 15x10 wheel. no problems with rubbing

matt_field · 08-27-2002, 09:19 PM

im running 32x10.50 bfg K.O. tires and 15x10 ultra wheels VERY NICE SET UP... no rubbing at all, my truck even sits stock . hope this helps

Mike C · 08-28-2002, 11:21 AM

I ran 33 14.5 MT Bajas on my Jimmy with 15x8" wagon wheels. No rubbing. Going to 10" rims caused slight rubbing on the fenders. (both with 3.5" backspacing) You could probably get away with 4" bs, but you shouldn't have any troubles with 31 10.5 except that a 7" rim is too narrow. Get yourself a set of six lug rallys off an 80's 4x4 or some aftermarket rims.

palallin · 08-29-2002, 01:02 AM

Quote:

Originally posted by Mike C
you shouldn't have any troubles with 31 10.5 except that a 7" rim is too narrow. Get yourself a set of six lug rallys off an 80's 4x4 or some aftermarket rims.

Why is it too narrow? (This is a genuine question; not a sm@rt-@$$ remark.) Is there danger or is it a "looks" thing?

I really dislike Ralley wheels, and I've never found an aftermarket set I like as much as the Center-cap and narrow trim rim combo I run now.

71BBK10 · 08-29-2002, 08:08 PM

i don't think you'll have any problems running that tire, i ran 35x 12.50's on like a 7 inch wide wheel (however wide 70's ford trucks are) with no problems good luck

**MJN** · 08-31-2002, 11:56 PM

The only reason that 7" wheels would be too skinny is that the wider the tire is the wider the rim must be for the sidewall to be it's strongest. If you put a fat tire on a skinny rim the sidewall is vulnerable to rocks and whatever else they encounter. They will also last longer as there will be less stress on the sidewall.

Mike C · 09-03-2002, 09:56 AM

It also allows you to run more PSI on the tire and still have even tire wire. With the narrow rim, the tread tends to bow up in the middle and you have to reduce pressure for even wear. This reduces the load the tire can carry. It also tendt to push the sidewall against the rim lip which means the load isn't carried on the bead in the proper area. A 10.5" tire should be on a 8-10" rim ideally, but the rim will be better protected offroading with an 8" width.

71BBK10 · 09-03-2002, 06:13 PM

after reading my post i guess i should clarify cause it does seem a little misleading, you can get away with running those tires on a 7 inch wide wheel (if you are a cheapskate like myself) but if you have the money to spare it would be better to go with something a little wider.

08-24-2002, 11:47 PM	#1
palallin Registered User Join Date: Jul 2002 Location: St. James, MO Posts: 1,238	How big a tire . . . What's the tallest tire one can run on a '69 K-10 withOUT lift or fender trimming? TIA. __________________ '69 Longstep K-10: 327/SM465/T-221/Closed Knuckle Dana44/12-bolt.

08-24-2002, 11:58 PM	#2
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	probably 32X10.5/15 on an 8" rim. Anything taller or wider will catch the front lip of the fender well. (I'm running 31x12.50R15s on 10" wide rims w/ 4" backspacing and with a little flex the tires hit the front lip of the fenderwell while turning.) This is even with new bushing for the stock 3 leaf springs and new poly body mounts and ORDs 1/2" longer shackles. i'm actually think of adding ORDs 1" zero add-a-leafs. I like the look of the wide tires. They are good for the sand. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

08-25-2002, 12:18 PM	#3
6869704X4 Registered User Join Date: Jul 2002 Location: SE NM Posts: 769	Before I lifted my 70 K10 I was running 33x12.50/15s on 70s rallys. No hitting anywhere and did some serious wheeling with it. Not sure of the backspacing on those factory wheels though. I can measure them for you if you want. __________________ The more I learn about women, the more I love my truck.

08-25-2002, 11:57 PM	#4
palallin Registered User Join Date: Jul 2002 Location: St. James, MO Posts: 1,238	So, I should be OK with 31s on 7" rims? __________________ '69 Longstep K-10: 327/SM465/T-221/Closed Knuckle Dana44/12-bolt.

08-26-2002, 09:24 AM	#5
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	most definately, i have 31x10.50's on a 15x10 wheel. no problems with rubbing __________________ 1971 K10 lwb fleetside 402 T350 205

08-27-2002, 09:19 PM	#6
matt_field Registered User Join Date: Apr 2001 Location: Detroit Lakes, Minnesota Posts: 885	im running 32x10.50 bfg K.O. tires and 15x10 ultra wheels VERY NICE SET UP... no rubbing at all, my truck even sits stock . hope this helps __________________ 1971 k5 blazer 80k mike survivor 1972 3/4 ton 4wd Cummins 12v 1967 swb 2wd 427bbc 1968 4wd shortbox 1971 Cheyenne swb k10 unrestored 1971 Cheyenne super 40k 402bb survivor 1967 Chevy k10 (first truck) 1968 L78 camaro survivor 18k miles 1969 z28 survivor 60k miles 1969 z28 survivor 39k miles 1969 z28 rs survivor 80k miles

08-28-2002, 11:21 AM	#7
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	I ran 33 14.5 MT Bajas on my Jimmy with 15x8" wagon wheels. No rubbing. Going to 10" rims caused slight rubbing on the fenders. (both with 3.5" backspacing) You could probably get away with 4" bs, but you shouldn't have any troubles with 31 10.5 except that a 7" rim is too narrow. Get yourself a set of six lug rallys off an 80's 4x4 or some aftermarket rims. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

08-29-2002, 08:08 PM	#9
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	i don't think you'll have any problems running that tire, i ran 35x 12.50's on like a 7 inch wide wheel (however wide 70's ford trucks are) with no problems good luck __________________ 1971 K10 lwb fleetside 402 T350 205

08-31-2002, 11:56 PM	#10
MJN Registered User Join Date: Feb 2000 Location: Maquoketa, Ia/ Orr, Mn Posts: 3,052	The only reason that 7" wheels would be too skinny is that the wider the tire is the wider the rim must be for the sidewall to be it's strongest. If you put a fat tire on a skinny rim the sidewall is vulnerable to rocks and whatever else they encounter. They will also last longer as there will be less stress on the sidewall.

09-03-2002, 09:56 AM	#11
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	It also allows you to run more PSI on the tire and still have even tire wire. With the narrow rim, the tread tends to bow up in the middle and you have to reduce pressure for even wear. This reduces the load the tire can carry. It also tendt to push the sidewall against the rim lip which means the load isn't carried on the bead in the proper area. A 10.5" tire should be on a 8-10" rim ideally, but the rim will be better protected offroading with an 8" width. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

09-03-2002, 06:13 PM	#12
71BBK10 Teufelhunden Join Date: Oct 2001 Location: Camp Pendelton Ca Posts: 572	after reading my post i guess i should clarify cause it does seem a little misleading, you can get away with running those tires on a 7 inch wide wheel (if you are a cheapskate like myself) but if you have the money to spare it would be better to go with something a little wider. __________________ 1971 K10 lwb fleetside 402 T350 205



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