would 23 kill my overdrive - The 1947 - Present Chevrolet & GMC Truck Message Board Network

paaw · 04-09-2007, 11:46 AM

I have 373 in my 72 and was wondering should I just put the twentys on there or some 23, how would 20 work with 700r and 373 (275/45/20)other (285/45/23)

1969 GMC · 04-09-2007, 01:33 PM

What was the overall height of your tires before vs. with those rubber bands?

If it's no different, then it won't affect your overdrive.

If the wheel/tire combo is slightly larger, it will actually reduce your rpm on the highway. If they are smaller, it will increase your rpm.

EDIT: most important to remember, it doesn't matter what size rims you have. It's all about the overall height of the tire/rim combo.

Bamm · 04-09-2007, 01:37 PM

Wow, I love big rims and big tires just as much as the next guy, but I would have to have more rubber between the rim and the road than that.

JMO ..............................Bamm!

67ChevyRedneck · 04-09-2007, 02:08 PM

The tires on my truck are 235/75R15 which are 28.88" tall.

I found this neat chart online. It only shows a 31.41 and 32.61" tire for the 23" rims. Considering lots of people run 31" tires on 4x4's, even modern trucks, I don't see why it would hurt anything?

http://www.sstire.com/tireheights.html

The other big question would be rear end ratio. If you have a 3.73 and OD I wouldn't worry about it. If you're running a 3.08 gear, with the larger tire, your truck may be lugging a bit.

paaw · 04-09-2007, 02:19 PM

the pic of the 20's on the 72 has 255/35/20 on the the 275/45/20 are a lot thicker they used to be on my caprice that is why the tires are small

kbs71 · 04-09-2007, 05:35 PM

here's a calulator. Just plug in wheel and tire size and it'ss give you MPH difference. http://www.miata.net/garage/tirecalc.html

04-09-2007, 11:46 AM	#1
paaw Registered User Join Date: Feb 2006 Location: nashville Posts: 217	would 23 kill my overdrive I have 373 in my 72 and was wondering should I just put the twentys on there or some 23, how would 20 work with 700r and 373 (275/45/20)other (285/45/23) Attached Images __________________ 1997 pontiac grand prix gt (daily driver) for now; 2004 dodge ram quad cab (wife's truck) 4.7; 2000 pontiac booneville (wife daily driver) 1972 chevy cheyenne 350 bored 40 over 700r trans 373 gears ( posi) soon to be daily driver; 2002 gsxr750 sold

04-09-2007, 01:33 PM	#2
1969 GMC Registered User Join Date: Feb 2003 Location: The Rubber City Posts: 5,498	Re: would 23 kill my overdrive What was the overall height of your tires before vs. with those rubber bands? If it's no different, then it won't affect your overdrive. If the wheel/tire combo is slightly larger, it will actually reduce your rpm on the highway. If they are smaller, it will increase your rpm. EDIT: most important to remember, it doesn't matter what size rims you have. It's all about the overall height of the tire/rim combo. __________________ 1969 GMC K2500 1996 Honda Accord 2007 Kawasaki KLR 650 Last edited by 1969 GMC; 04-09-2007 at 01:34 PM.

04-09-2007, 01:37 PM	#3
Bamm Cowboy Fan for Life!!!!!! Join Date: Apr 2002 Location: Amelia, Virginia Posts: 2,921	Re: would 23 kill my overdrive Wow, I love big rims and big tires just as much as the next guy, but I would have to have more rubber between the rim and the road than that. JMO ..............................Bamm! __________________ 1967 ShortBed Fleetside 3/4 Drop 350/700R4 Tilt wheel 18 x 8 Torque Thrust II's Future mods: All new gauges & wood bed My Zip is 23002 I ship UPS, USPS

04-09-2007, 02:08 PM	#4
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: would 23 kill my overdrive The tires on my truck are 235/75R15 which are 28.88" tall. I found this neat chart online. It only shows a 31.41 and 32.61" tire for the 23" rims. Considering lots of people run 31" tires on 4x4's, even modern trucks, I don't see why it would hurt anything? http://www.sstire.com/tireheights.html The other big question would be rear end ratio. If you have a 3.73 and OD I wouldn't worry about it. If you're running a 3.08 gear, with the larger tire, your truck may be lugging a bit. __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications!

04-09-2007, 02:19 PM	#5
paaw Registered User Join Date: Feb 2006 Location: nashville Posts: 217	Re: would 23 kill my overdrive the pic of the 20's on the 72 has 255/35/20 on the the 275/45/20 are a lot thicker they used to be on my caprice that is why the tires are small __________________ 1997 pontiac grand prix gt (daily driver) for now; 2004 dodge ram quad cab (wife's truck) 4.7; 2000 pontiac booneville (wife daily driver) 1972 chevy cheyenne 350 bored 40 over 700r trans 373 gears ( posi) soon to be daily driver; 2002 gsxr750 sold

04-09-2007, 05:35 PM	#6
kbs71 71 rustless in texas Join Date: Aug 2004 Location: Houston, TX Posts: 257	Re: would 23 kill my overdrive here's a calulator. Just plug in wheel and tire size and it'ss give you MPH difference. http://www.miata.net/garage/tirecalc.html __________________ "The secret to creativity is knowing how to hide your sources." "No one really listens to anyone else, and if you try it for a while you'll see why" 71 C-10 LWB presently in a perpetual state of disassembly '96 Toyota (my work car) '04 Mustang Convertable (wife's car & other money pit) Latest aquesition and why my trucks still in the garage covered with junk.. 2010 Aqua Blue metallic 6 speed Manual LS3 2SS/RS Camaro (I want one of these in my truck FAQ here VENDORS here SUPPORT THE BOARD here My second favorite SITE



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.