Need some info on correct backspacing for new wheels

[1972SUPERSB]

I will be purchasing some new torq thrust 2 wheels soon. I need to know what would be the best fit for my truck. Mine is a 72 and will be at stock height. What backspacing should I get for the front and back? If anyone has any pics of what they have with the backspacing that would be great. I would like the front and back to be pretty flush with wheel wells. Any help would be appreciated. Thanks !
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[GEARBOXGARAGE]

These are an 18" x 9.5" with 4.75" back spacing with the earlier (Pre-'71) rear end length. '71-'72 rear ends were about 1/2" wider per side.

[1972SUPERSB]

Originally Posted by GEARBOXGARAGE

These are an 18" x 9.5" with 4.75" back spacing with the earlier (Pre-'71) rear end length. '71-'72 rear ends were about 1/2" wider per side.

Ok so if I got 17 x 8 wheels I would prob need a 5" backspace in the back and 4" in the front?
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[GEARBOXGARAGE]

I think 5" b.s. would be too much on an 8" rim. That would push the wheel/tire in too far. The shallower the b.s., the farther ther wheel/tire will come out. Are you running the same size tire front and rear or staggered sizes? A pretty common b.s. for an 8" wheel is 4.5". That's what I will be running on the front, 18 x 8 w/ 4.5" b.s. Even with the wider 9.5" wheel with the 4.75" b.s., you can see it's tucked in just a bit, and a narrower wheel would be in even farther. I may have some time this weekend to swap out the wheels and put the 8" on for comparison and show you the difference. Or perhaps others may be able to post up some pics as well.....

[lolife99]

20X8 (5" BS)
20x9.5 (5" BS) with the wider 71-72 rearend)

This is what I would run.
This is where the arguments come into play.
Everyone likes them to look different.
I like them under the fenders.

The real answer is to get out your tape measure and straight edge,... and measure yourself.
Every thing else is just someones opinion.

[1972SUPERSB]

Yeah I definitey don't want them sticking out. So less backspacing will push wheels farther out? Does anyone have a 8" wheel in the back they can show me with the backspacing they have? Thanks guys for the info. I am thinking of running 17 x 8 all the way around. Looks like lots of people run 255/60/17 tires. Not sure what eveyone else uses on a 8" wheel. I may look into using a 17 x 9.5 wheel in the rear. Seems to be pretty popular. What size tire would be used for the 9.5 wheel?
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[GEARBOXGARAGE]

This truck was in Classic Trucks Magazine a few years ago, running 17's all the way around w/ 275/50R17 tires. Can't remember the wheel width specifically.....

What size are you currently running? Your best baseline info is right on your truck already. Measure what you are currently running and add or subtract from there.

[1972SUPERSB]

Originally Posted by GEARBOXGARAGE

This truck was in Classic Trucks Magazine a few years ago, running 17's all the way around w/ 275/50R17 tires. Can't remember the wheel width specifically.....

What size are you currently running? Your best baseline info is right on your truck already. Measure what you are currently running and add or subtract from there.

I just have some rallies with 255/70/15
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[Daaaanz67]

Here's a picture of my truck. 69c/10 already converted to 71 front and rear axle. Wheels are 17x8 with 5.5 offset. These actually came off my 97 pu I once had so I didnt buy these for this truck. If you carefully look you can see how tucked they are. In my own opinion for the rear if I had to do it again I would probably go for 4.75 offset for rear. The rear rubs now when I make turns which make the frame or suspension twist. Even with 5.0 I think it's still to close for comfort. I'm even using adjustable track bar for centering. Probably same offset for front just cause I like the even look just my .02c. Im rolling on rallies at this time but if I put these back on will be using a spacer.
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[Daaaanz67]

Here's one I ran into the other day hope the owner doesn't mind me posting. Truck was awesome the look I'm looking for and hoping to run into the owner to get more specs. Also think he lives in my town. Don't know the offset but I don't think there 5.5 or 5.0. Tires are 255/50/17 front 275/50/17 rears.
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[lolife99]

Offset and wheel backspacing are too different things.
Don't get these numbers mixed up.

[Daaaanz67]

Sorry should of said bs
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[1972SUPERSB]

Originally Posted by Daaaanz67

Here's one I ran into the other day hope the owner doesn't mind me posting. Truck was awesome the look I'm looking for and hoping to run into the owner to get more specs. Also think he lives in my town. Don't know the offset but I don't think there 5.5 or 5.0. Tires are 255/50/17 front 275/50/17 rears.
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Thanks for the pic. I'm curious what his backspacing is?
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[1972SUPERSB]

[QUOTE=lolife99;5680215]Offset and wheel backspacing are too different things.
Don't get these numbers mixed up.[/

If you have an offset of -19mm doesn't that convert to like 3.75 backspacing?
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[502ms]

15x8 4.25 backspacing
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