31" tires & 3.08 rearend! How many problems? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Sooner1970_K10 · 02-18-2005, 11:10 AM

I currently have a 3.08 rearend in my k10. I have decided to make do with my original rims and no lift kit untill a later date. The tires on the truck are mismatched and ratty looking. I decided I atleast wanted to replace them. I am also going to get the old rims stripped and powder coated (white) for around 40 bucks a piece.

Currently the truck has 235/75/15 which is around a 28" tall tire and 9"ish wide.

The tire gear ratio guide states that anything over a 28" wheel is not advised for a 3.08 rearend.

Mind you, this truck is only for driving to town and maybe an occasional small load. No hauling or offroading will take place.

Question: Am I asking for trouble if I run 31x10.50x15 tires on a 7" (stock) rim with a 3.08 rearend? Will it hurt anything, handle bad? How much performance decrease would I be able to see.

Question: Any advice on the best place to get some BFG's in the above size? I will call around and find the best $$ price but as far as service or warranty what would you guys suggest? In the past I have compared 4wheelparts local store, sears, and a couple of the local tires shops.

CHEVYE · 02-18-2005, 11:23 AM

my 84 big block truck has 2.73 gears and i am running the exact same tires (31/10.50/15). i`ve never had a single problem with it. i am curious why it says that though???

Longhorn Man · 02-18-2005, 12:18 PM

It'll be a bit more of a dog off the line, but not too much.
NFC as to why they wouldn't recomend it though.

CHEVYE · 02-18-2005, 12:36 PM

Quote:

Originally Posted by Longhorn Man

It'll be a bit more of a dog off the line, but not too much.
NFC as to why they wouldn't recomend it though.

mine does "decent" off the line..... it`s a champ on the interstate though.

junkyardjohn · 02-18-2005, 12:43 PM

I'VE GOT A 71 K5 BLAZER WITH 32/1150/15 BFG ALL TERRAIN T/As ON IT, & I'M RUNNING 308 GEARS, WITH A PRETTY STOCK 355. NO PROBLEM WHAT SO EVER.

JOHN

Sooner1970_K10 · 02-18-2005, 01:15 PM

Great! thanks for the responses.. Now I dont have to dread anymore!

Chevy Muscle · 02-18-2005, 02:01 PM

I have 33x12x15 s with my 3.07 rear in my K5 (PO said it was 3.73

)

.... and it does just fine off the line and great on the freeway with a realitivly stock motor.

I just wonldn't suggest putting a long duration cam in your engine.

02-18-2005, 11:10 AM	#1
Sooner1970_K10 1970 K10, 350, 4spd! Join Date: Jun 2004 Location: Shawnee, Ok Posts: 128	31" tires & 3.08 rearend! How many problems? I currently have a 3.08 rearend in my k10. I have decided to make do with my original rims and no lift kit untill a later date. The tires on the truck are mismatched and ratty looking. I decided I atleast wanted to replace them. I am also going to get the old rims stripped and powder coated (white) for around 40 bucks a piece. Currently the truck has 235/75/15 which is around a 28" tall tire and 9"ish wide. The tire gear ratio guide states that anything over a 28" wheel is not advised for a 3.08 rearend. Mind you, this truck is only for driving to town and maybe an occasional small load. No hauling or offroading will take place. Question: Am I asking for trouble if I run 31x10.50x15 tires on a 7" (stock) rim with a 3.08 rearend? Will it hurt anything, handle bad? How much performance decrease would I be able to see. Question: Any advice on the best place to get some BFG's in the above size? I will call around and find the best $$ price but as far as service or warranty what would you guys suggest? In the past I have compared 4wheelparts local store, sears, and a couple of the local tires shops.

02-18-2005, 11:23 AM	#2
CHEVYE my gas saver Join Date: Sep 2003 Location: Clarksville, TN Posts: 2,046	my 84 big block truck has 2.73 gears and i am running the exact same tires (31/10.50/15). i`ve never had a single problem with it. i am curious why it says that though??? __________________ 85' SWB, 4.3/TH350, getting ready for paint 84`SWB, 462ci./TH400, cowl hood, 15" billet spec., flows, blazer buckets/console, flat black 71`SWB, project ebay feedback

02-18-2005, 12:43 PM	#5
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	I'VE GOT A 71 K5 BLAZER WITH 32/1150/15 BFG ALL TERRAIN T/As ON IT, & I'M RUNNING 308 GEARS, WITH A PRETTY STOCK 355. NO PROBLEM WHAT SO EVER. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

02-18-2005, 12:18 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	It'll be a bit more of a dog off the line, but not too much. NFC as to why they wouldn't recomend it though.

02-18-2005, 01:15 PM	#6
Sooner1970_K10 1970 K10, 350, 4spd! Join Date: Jun 2004 Location: Shawnee, Ok Posts: 128	Great! thanks for the responses.. Now I dont have to dread anymore!

02-18-2005, 02:01 PM	#7
Chevy Muscle < 69 Blazer Join Date: Mar 2004 Location: Nevada, TX Posts: 292	I have 33x12x15 s with my 3.07 rear in my K5 (PO said it was 3.73 ) .... and it does just fine off the line and great on the freeway with a realitivly stock motor. I just wonldn't suggest putting a long duration cam in your engine.



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