wheel and tire sizes please

[USA69Z]

G'day all , im new to the truck scene (in australia) and have just purchased a 1970 stepside C10. The truck has huge tru spoke rims front and back which i have to change (they stick out ) .. so my age old question is on wheel sizes and backspace for these trucks.. I have seen a couple of pics of guys with 20 x 10s front and rear ?? with a 275/35 tyre on the rear ? i do want it to be kinda low ,, whats the optimum backspace for these stepsides ..

thanx !

Gav Downunder

[gcburdic]

ttt

[USA69Z]

no one knows? geez i thought someone may have changed there rims along the way.?

[Lloyd C.]

My 68 stepside is down 7" in the rear and 5" in the front. I'm running 17x10's on the rear with 275/55/17 and 17x8's on the front with 275/55/17. Sorry, I can't give you the back set without doing some digging but I do know I can barely get my fingers between the rear tires and the box on the inside and, yes, they do occasionally rub on the outside when I hit a dip in the road. That's just the cost of looking cool. However, you can roll the flange on the inside of the rear fenders up a bit which definitely helps. Most tire and wheel shops will work with you on trying different back sets until you find what works.

[Lloyd C.]

Whoops, I meant 225/55/17 on the front.

[Jay W]

Try a search there is a ton of threads about it. Do you know if you have the narrow rearend, I think 1970 came with both the 64 and 65.5" wide rear end. (im not 100% about the widths)

Best to measure for backspacing but i would expect you could run a 275/40r20 out back and I would go 255/40r20 up front or you can go 285/50r18 and 255/50r18.

I know the fleet sides can handle a 295 wide but im not as familiar with stepsides.

[CC69Rat]

I am running a 255/45/20 on a 20x8.5 with 4.75" Backspacing on the rear. It could handle 255/50/20 .. but it would be very tight. This is on a 6" drop with the narrower (67-early 69) rear end housing. I stayed with the 45 on the rear so I wouldn't need to lower it any more. I am going to notch it and add 1" block as soon as I can.

The fronts are 255/40/20 on a 20x8.5 with a 5.5" Backspacing. I also have the 73+ front cross member swap with HD front rotors so it added about .5" track width in the front on either side. Normally guys run the same size wheel / tire with a 5.25" backspacing but I pushed mine back a little more to accomodate the extra track width.

The largest rear tire/wheel I have ever seen on a stepper is 285/35/22 on a 22x9 with 5" Backspacing. Early rear end, .. but it does require trimming on the outer lip. A 265/40/22 on this same wheel is perfect on a bagged stepper IMO. Some guys run 10" wide and that's cool I just like for my tire to be a little wider than the rim width.

There is a whole lot more room under a fleet than a stepper. I have a BB too, so I didn't want to be getting into the tires on hard acceleration.

[Lloyd C.]

Ah hah. It's been six years since I built my 68 stepside, so I had to do some digging on my wheel sizes and back sets, but here it is. As I mentioned earlier, I'm down 7" in the rear and 5" in the front. I do know the stepsides are a little tighter on the rear fender space than the fleetsides, so you have to measure carefully. I rolled the inner fender flange of the rear fenders in a bit to give me a little more clearance. My wheels are 8 spoke Eagle Alloys, style 114. Rears are 17 x 10 w/ 4 1/2" back spacing, running a 275/55/17 Dunlop. Fronts are 17 x 8 w/ 4.4" back spacing, running a 225/55/17 Dunlop. Hope this is of some help.

[CC69Rat]

Got some pics? I bet it looks really good

[Lloyd C.]

I'm a 72 year old 'Techno-peasant" who hasn't yet figured out how to attach a photo, but I'll give it a shot.

[USA69Z]

thanx guys ! i appreciatte all the advice,, ill try for a pic.. my truck is still on the back of a transport truck being delivered to me down the east coast of australia after being brought over by ship.. so i havnt (and didnt know) about diff sizes and if it a 5 or 6 stud yet.. sould arrive in next couple of days ,, i own a 69 camaro as well which is converted to RHD,

[CC69Rat]

Wow! Both look great! I love the Camaro too. Is it really dark blue or black?
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[USA69Z]

thanx! , she's black with a mett grey hockey stripe ,, fast injected crossram 383 sbc , 6 speed tremec , right hand drive etc etc...

[CC69Rat]

I have restored a couple 69's myself but they are very expensive to build here in the states. I love the Rally Sport front end too ! Great job.

[n2billet]

Here's what I've got on my 71...with an early rear end

Front:
20x8.5 with 5.25bs 255/40/20

Rear
22x9 with 5.00 bs 265/40/22

[Chevyman680063]

Originally Posted by USA69Z

thanx guys ! i appreciatte all the advice,, ill try for a pic.. my truck is still on the back of a transport truck being delivered to me down the east coast of australia after being brought over by ship.. so i havnt (and didnt know) about diff sizes and if it a 5 or 6 stud yet.. sould arrive in next couple of days ,, i own a 69 camaro as well which is converted to RHD,

You sir have one of my #1 dream cars, and it has the RS grille which is an added plus. Very nice Camaro and C10! One more thing...

[USA69Z]

thanx guys for the warm welcome.. a bit of an update on my 70 stepper truck .. i now have had it for 2 whole weeks.. the wheels are 'weld wheels 15 x 10 tru spokes' front and rear. they all have 4 inch backspace. 245/60 front and 275/60 rear tyres. the rears stick out bad. there pretty rusty or 'rooted' as us aussies say ! im shopping around for something to replace them with.. Im thinkin satin centerlines in 15s for now as the tyres are brand new.
it seems it has drop spindles, and is 5 on 5 pattern so its had power discs put on and diff changed ? 350sbc , t400 box and 10 bolt diff. also the rear tail lights have been 'frenched' into the bed .. woulda been a nice thing back in the day but it has been neglected pretty bad and needs a lot of work.

Gav

[brans72]

see you got taste with Rushforth wheels and there is n2billet rubbing it in again with his sweet rides. That must be his d/d now instead of hazel.

[sharpmark]

gidday mate-welcome to the site.
looks like you got an interesting project in front of you with the c/10!!
isn't it fun ordering parts out of the states! some of them are good to deal with and others are pretty damn frustrating!
camaro looks bloody great - how come you had to convert it to righthand drive?

[USA69Z]

Originally Posted by sharpmark

gidday mate-welcome to the site.
looks like you got an interesting project in front of you with the c/10!!
isn't it fun ordering parts out of the states! some of them are good to deal with and others are pretty damn frustrating!
camaro looks bloody great - how come you had to convert it to righthand drive?

Mark? ,, i didnt have to convert it ,, i just wanted to after owning a few left hookers over the years . I guess it was part of the overall project as we done it ourselves (with help from an engineer)