What is biggest size tire I can fit under my pickup?

[bazkook]

I have a 1970 Chevrolet C-10 pickup that I am restoring. I want to go for the Pro Street look with the big rear tires,both for maximum traction and good looks, and skinny front tires. I plan on lowering the truck about 2 inches as well. I want to get the biggest tires in the rear,in diameter and width, as possible without them rubbing or interfering with other components or without resorting to a narrowed rear end or tubs. I will probably just go with 15" wheels BTW. What's the biggest I can go? Also what kind of backspacing will I need? Is there a chart on the internet where I can look up tire sizes for particular vehicles?

[Big White GMC]

It Depends On How Wide Your Wheels Are, Backspacing, Ect. I've Got 15x8.5 Wheels And Have Had 255/70/15 Eagle Gt II Tires On It. I Had A TON Of Room Left Up Front. If Your Gonna Go Pro-Tour I'd Suggest A-Arm Upgrades ( Tube ) And A Spring Change First Off. A Little More Money Spent But A World Of Difference As Far As Ride And Grip. As Far As Tires.... Couldn't Tell You. From Personal Experience, I'm Enjoying My New Toyo Proxes ST's. They Are 275/60/15. They Will Help As Far As Sidewall Flex And Wet Traction. Out Back, I'd Do Springs, A New Panhard Bar ( Assuming You Have Trailing Arms. ) , And Sway Bar. Early Classic Has All Of That Stuff. Good Luck, Man. Let Us Know What Happens.

[Bob 68327]

I have 15x11 with 5 1/4 backspacing 275 60 15 bfg with no clearance issues

[Richard H.]

bump,

[bazkook]

Originally Posted by Big White GMC

It Depends On How Wide Your Wheels Are, Backspacing, Ect. I've Got 15x8.5 Wheels And Have Had 255/70/15 Eagle Gt II Tires On It. I Had A TON Of Room Left Up Front. If Your Gonna Go Pro-Tour I'd Suggest A-Arm Upgrades ( Tube ) And A Spring Change First Off. A Little More Money Spent But A World Of Difference As Far As Ride And Grip. As Far As Tires.... Couldn't Tell You. From Personal Experience, I'm Enjoying My New Toyo Proxes ST's. They Are 275/60/15. They Will Help As Far As Sidewall Flex And Wet Traction. Out Back, I'd Do Springs, A New Panhard Bar ( Assuming You Have Trailing Arms. ) , And Sway Bar. Early Classic Has All Of That Stuff. Good Luck, Man. Let Us Know What Happens.

I was going to upgrade the suspension of course, mainly to go straight. The truck has been sitting for a long time anyway so I figure now's the time to do it. I will probably put some traction bars in the rear and a fuel cell and battery in the bed to get some weight back there. BTW, I don't know whether this makes a huge difference or not but I have a stepside. I've heard stepsides can fit fairly big tires but how much bigger than fleetsides I don't know.
As far as tires go, I've been looking at either the M/T Sportmans or ET Drag Radials. ET Drag Radials come up to about 29" so I fairly sure they'll fit no problem. But I would like the tire to fill up the wheelwell as much as possible.

[Bob 68327]

Here's another truck I built 15 x 10 slots with 31x10.5x15 with 4''back space wheel lowered about 4'' no clearance issues.

[1970bowtie]

i got 15X10's with 295/50's, not sure of back spacing but their American racing outlaw 2

[bad6772]

in the rea i run a 335x55-17, i will check back spacing for you, my rear rim is 12 inches wide and although it is very close to the inner wheel tub.qbout 1/2 inch. ive never had any rubbing problems, unless i got on it hard from a dead stop. with a posi unit. it tends to get a little sideways from time to time

[bazkook]

When I get the truck drivable,I'll see if the local tire guy,whom I know well and have done a lot of business with, will let me use some extra tires he's got laying around to see what will fit and what won't.

[Big White GMC]

These Trucks Can Run Some Big Tires With Not Much Of A Fuss. Stepsides Are Able To Handle About Anything You Can Throw At Them. BTW, Are You Lowering The Truck? Cause If So, That Throws A Few More Wrenches Into The Works. As Long As You Don't Go Crazy With The Drop, You Can Run Whatever.A 2/4 Drop Is Good, But Anything Lower You Run Into Front Clearance Problems.

[bazkook]

Originally Posted by Big White GMC

These Trucks Can Run Some Big Tires With Not Much Of A Fuss. Stepsides Are Able To Handle About Anything You Can Throw At Them. BTW, Are You Lowering The Truck? Cause If So, That Throws A Few More Wrenches Into The Works. As Long As You Don't Go Crazy With The Drop, You Can Run Whatever.A 2/4 Drop Is Good, But Anything Lower You Run Into Front Clearance Problems.

I'm not into slammed trucks so I won't go crazy with the drop. However,I have the stepside with the spare tire on the driver's side and the cutout in the wheelwell. Will this be a problem trying to fit a big tire on the driver's side?

[Big White GMC]

Yeah, I Could See That Spare Tire Hump Being A Problem. You Could Move The Spare Under The Bed, Unless You're Going To Put The Gas Tank There. Then I Guess You'll Have To Go Commando, So To Speak.Worse Case Is A New Wheel Housing On That Side Of The Truck. I've Never Liked The Idea Of That Spare Tire Holder On The Side Of The Bed.Too Easy For " People " To Gank Your Spare.American Racing Has A Program That Shows Their Wheels On Your Truck. That Might Help.

[bazkook]

Originally Posted by Big White GMC

Yeah, I Could See That Spare Tire Hump Being A Problem. You Could Move The Spare Under The Bed, Unless You're Going To Put The Gas Tank There. Then I Guess You'll Have To Go Commando, So To Speak.Worse Case Is A New Wheel Housing On That Side Of The Truck. I've Never Liked The Idea Of That Spare Tire Holder On The Side Of The Bed.Too Easy For " People " To Gank Your Spare.American Racing Has A Program That Shows Their Wheels On Your Truck. That Might Help.

I'll probably just ditch the spare altogether. I plan on using a fuel cell in the bed anyway and take the gas tank out of the cab. I might just have to use a new fender anyway because the original is pretty rusted,just like the rest of the truck. I never liked the spare tire holder on the side either. It seems to me that it would really shift the weight to the driver's side more.

[70cst]

I have 275x60x15 on all fours and I am have a slight rubbing issue on the fronts. I have a 2-4" drop. Truck is a 70LWB. The wheels are 15x8 5 lug truck ralley's. I think I will drop to a 225x15x60 up front so I get away from the rubbing issues. I too thought I would have plenty of room up front but not so.

[Big White GMC]

Originally Posted by 70cst

I have 275x60x15 on all fours and I am have a slight rubbing issue on the fronts. I have a 2-4" drop. Truck is a 70LWB. The wheels are 15x8 5 lug truck ralley's. I think I will drop to a 225x15x60 up front so I get away from the rubbing issues. I too thought I would have plenty of room up front but not so.

I'd Go 255/60/15 On The Front. A 225 Would Look Tiny Compared To The 275's Out Back.

[70cst]

Thanks Big White GMC on your recommendation. After reading your suggestion I think you are right. I will go as large as possible w/o rubbing. Thanks again!!!

[68Stepbed]

I would also suggest the 285/70/15 rear with a 235/70/15 front for a prostreet look. If you want good traction, look at some of the drag radials. I think Mickey Thompson makes a 295/60/15, which is about 29.5" tall. I've seen 6" rear drops without clearance issues with these tall tires.