The official Tire and rim Thread!

[HI WINDING MONZA]

For you drag racers still using a 13'' diameter rim, a 21.5" tall X 8.0" wide x 13" slick will fit on a factory offset stock hubcap type steel rim without rubbing on the inner quarterpanel.

Doug in Az

[clintjohns]

Found some Iroc Z wheels and wanting to put them on my 79 sunbird. Converted over to the 4.75 lug pattern. Anybody running these size tires - and if so any major problems, I don't mind a little rub every now and then when you turn sharp

245/50/16

[bill1978v8]

I'd like to know how the fit. I have a set of 4 gen Z28 wheels I'd like to put on with 245/45-16's.

Bill

[spyder_xlch]

IROC is 3rd gen. Aren't 4th gen wheels different back spacing?

[clintjohns]

didn't think you could run the 4th gen wheels to the backspacing. aren't those wheels basiclly all back spacing

[spencerforhire]

4th gen F-body wheels (like C4 and up Vette) can only be used with a 2 or 2.5" spacer; they have the ridiculous 6.875" backspacing. They might fit on the back if you used a Camaro width rear end, and if you're shop is equipped with a lathe and a TIG, you might be able to narrow the front ones by about 3"...... Sounds like a lot of work. I almost fell in this "hole" myself a few years ago when I found a set of 1986 Vette wheels for $250; I thought they'd look cool on a lowered S-10 I was building, until I found out that I'd need a $300 set of spacers to use them!

[Astre-mutt]

4th gen F-body wheels (like C4 and up Vette) can only be used with a 2 or 2.5" spacer; they have the ridiculous 6.875" backspacing. They might fit on the back if you used a Camaro width rear end, and if you're shop is equipped with a lathe and a TIG, you might be able to narrow the front ones by about 3"...... Sounds like a lot of work. I almost fell in this "hole" myself a few years ago when I found a set of 1986 Vette wheels for $250; I thought they'd look cool on a lowered S-10 I was building, until I found out that I'd need a $300 set of spacers to use them!

Just for the record, 4th gen wheels fit AWD S10's. You could use a rear end from a 4X4 Chevy S10, and the wheels should fit. This won't help you on the front, but could be an option if you plan ahead when you do a rear end swoop. (8.5" ZR2 swoop anyone?)

[73Sedan]

Year/Make/Model of car: 1973 Notchback Vega
Rear end type: Autoweld replacement 9" (factory fit 4 bar)
Brakes (disc or drum): Aerospace disc kit for Ford Large
Width (if known): Exactly the same as original 6.5" 4 bar rear
Rear rim size: 18x9JJ (BMW M5 wheels - also the same as late model Camaros)
Rear rim backspacing: Have to add 15/16" hub-centric billet adapter to the BMW offset
Rear tire profile and size: 275/35-18 (HUGE!!!!!)

REAR SPRINGS: Moog/TRW CS5659 (no idea what they are for, but they raise the rear 1.25")

BMW 5 series use 5 on 120mm . . . Chevy 5 on 4.75" is the same as 5 on 120.7mm. SO, by the time you split the 0.7mm 5 times, you can still use acorn lugs to secure the wheels (FOR STREET USE ONLY!!!!!!) DO NOT USE THIS METHOD FOR DRAG RACING!!!!! When I finally get this B!TCH running, she will have a second set of wheels specifically used for the track. **Thanks Spencer for the correct sizes, I'm not the wheel expert and was trying to rattle off what I could remember - I still don't get why some wheels list BOTH backspacing AND offset.

I will be putting the M5 18x8's on the front - it will be a while as I still have to further notch the 1-piece oil pan for the grease fittings to clear.

Anyway, I was SO happy to get the rear results - so photos follow: (NOTE: engine and trans are in the car in these photos, rear end is resting on the axle - springs used have NO upward movement left - shocks are at maximum upward travel at resting weight)

[spencerforhire]

4.75"=120.65mm; BMW bolt pattern listed as 120mm. Pretty close;I'm sure the studs will deflect around .32mm or .0126" (which is not a very large amount). I've also seen 4x4" (101.6mm) bolt pattern vehicles with 4x100(3.94") wheels on them, which is a bigger difference.

[clintjohns]

Year/Make/Model of car: 1979 FORMULA SUNBIRD
Rear end type: STOCK W/ S10 GUTS AND 3.73 GEAR
Brakes (disc or drum): FRONT S10 DISC - REAR DRUM
Width (if known): STOCK
Rear rim size: 16"
Rear rim backspacing: WHATEVER IROC Z WHEELS HAVE
Rear tire profile and size: 245/50/16
Front rim size 16"
Front tire profile and size: 205/35/16

[jdmrh07]

Year/Make/Model of car: 1975 Chevy Monza -aka "DaiMon 358"
Rear End type: Narrowed 12 Bolt
Rear End width: stock dimensions
Brakes: front & rear disc
Rear Body width: 3 inch fender flares
Rear height: 2 inch lift kit
Rear Wheel size: 15x12"
Rear Wheel backspacing: 5 1/4
Rear Tire profile and size: 325/50/15

Front Body width: rolled fender wells
Front height: 2 inch drop spindles
Front Wheel size 15x7"
Front Tire profile and size: 205/55/15
Front Tire backspacing: 3 3/4


...The Phantom of the H-body Organization... Surfacing once again... You'd think one of these days I'de update my profile with some recent pics...

[Theeviltowncoupe]

Ok...now I'm getting the picture...I haven't seen too many coupes, though. I noticed that the only one stated he used a .50 spacer on the rear. My big thing is to not have to end up with the 70s Motion Baldwin look...cool for the time, but not my cuppa, if ya know what I mean. Anyone else with a coupe out there got more information?

[jdmrh07]

My big thing is to not have to end up with the 70s Motion Baldwin look...cool for the time, but not my cuppa, if ya know what I mean.

nope I don't know what you mean... maybe you could explain it a little better for me...

[283vega]

I think he means he doesn't like the rear end jacked up and the tires sticking out beyound the fenders look.Or at least thats what I understand him to be saying.

[Theeviltowncoupe]

EGGS-ZACTLY.

Don't really feel like peeling rubber off of my tiny little quarter windows. Besides, I nearly fell down a flight of stairs wearing bell bottoms, once.

Brian