Wheel and tyre size for XB falcon sedan

[Stumps 384]

Hi Guys,

 

I recently picked up a very clean low kay (76000km's) XB falcon 500 sedan and I'm looking at putting some decent wheels on her to give her the look she deserves, it currently has the stock 14in wheels with 205 rubber and looks pretty ordinary, for some strange reason the arse end has been lowered 1 inch with lowering blocks which I intend to get rid of...I hate those damn things.

 

I'm not intending to lower the arse end as they sit pretty low from stock, but I'll knock an inch out of the front to bring things more in line.

 

I need to find out if the wheels and tyres I'm looking at will fit under the arse end without having to roll the guards.

 

I wanna fit B45's or V5's in 15x8 on the front with 245 tyres and 15x10 with 265 or 275 rubber on the bum. 

 

Will these fit the sedan? I have seen plenty of XB's with 10's on the bum in the past but never really bothered to look at the actual fitment.

 

[deankxf 21,501]

if you don't care about keeping the drums on the rear, the XR to XY diffs are narrower (might need a different universal joint, we fitted one to an ZG fairlane about 30yrs ago from an XR and it had different diff yoke, which can be swapped over also to the XB type)

 

as for max

fitment? no idea, but the rear can be narrower with a diff swap

[Stumps 384]

hmmm interesting.

 

Also does the stub axle diameter matter, my XB has the small stub axle (63.5mm) and most wheels I have seen have 73.1mm for the bores, is this going to be a safety issue or do I need to upgrade these to a later model?,  I have a complete XG falcon ute that Im going to part out for it's T5 to go in the XB, so it has discs all rounds and are in good working order.

[deankxf 21,501]

1 minute ago, Stumps said:

hmmm interesting.

 

Also does the stub axle diameter matter, my XB has the small stub axle (63.5mm) and most wheels I have seen have 73.1mm for the bores, is this going to be a safety issue or do I need to upgrade these to a later model?,  I have a complete XG falcon ute that Im going to part out for it's T5 to go in the XB, so it has discs all rounds and are in good working order.

yeah you can get "HUB CENTRIC" inserts for wheels or the hubs depending on what's available.

the XG front discs could be a direct fit to the front of an XB..
the diff will be a direct bolt in, will need a brake nut change at the T piece on the diff if using the XB hose from the body to the diff. or you can get an adapter to go from imperial to metric and use the XG T piece hose (20yrs newer ) 

hand brake cable will need mods/remade or POSSIBLY an EB sedan one might fit?(seen them into XD, but not older)

XG diff is as wide as the XB one, possibly slightly wider though. 
XG diff has 28 spline axles and XB 25 spline, nothing will interchange on those diffs to my understanding. 

 

[bear351c 10,565]

Yeah, had trouble with offsets on the rear wheels on my XB sedan, the aftermarket Globes are a deeper dish (made by Castalloy/ROH back in the day) and they stick out and hit the guards, with a 245 tyre. Had a 9" shortened, and ran a 3/4"spacer (I Think ?) just to get the look I wanted. Didnt want to roll the guard lip, as it has the Fairmont stainless trims. 

 

 

 

[JG33 38]

The XC GS I owned years ago has 15x9.5 Centerlines with a 5in backspace and 265 tryres, no issues with guard rubbing.

 

[Stumps 384]

wow that XC looks awesome, love those big girls....thanks for the info guys, might push a head and see what happens, might back off to 8.5 or 9 on the bum to be safe, been speaking to the local mechanic who's going to be replacing the old 3 on a tree with a T5 and he reckons that I wont see much of a track increase doing the XG diff at the same time. I can always get the 10's at a later date when the car and suspension is sorted.

[deankxf 21,501]

4 hours ago, Stumps said:

wow that XC looks awesome, love those big girls....thanks for the info guys, might push a head and see what happens, might back off to 8.5 or 9 on the bum to be safe, been speaking to the local mechanic who's going to be replacing the old 3 on a tree with a T5 and he reckons that I wont see much of a track increase doing the XG diff at the same time. I can always get the 10's at a later date when the car and suspension is sorted.

have you seen the T5 adapting to 3 speed/4 speed bell housing?  
there's a thread on it here (the XG bell housing won't fit, well are you doing the XG engine, if so, then no issue, it will go in no problem)

 change the speedo gear to the one that matches the diff in the car (3 speed one should fit the T5, just clips off.. keep the old t5 gear for the XG diff if doing it later)

tailshaft yolk might be different from 3 speed if manual (auto on the tree, going to need a different bell housing also, but the tailshaft would fit the T5)

[SPArKy_Dave 9,427]

XG front discs have larger bearings I believe, plus the larger diameter hub, same as XG rear

The XB spindles may be smaller diameter too, I believe?

 

10's fit on the coupes, but I don't think they fit on any others without quarter panel modification

 

[Stumps 384]

I plan on swapping the entire stub axle caliper assembly of from the XG, upgrading the brakes from XB to XG. I'll probably use the power steering as well, seeing as the rest of the car is getting an upgrade to XG.

Still trying to figure out what to do about the engine...I have a rebuilt 2v head and Manifold in the shed...I was thinking of fitting low comp pistons, sniper EFI and a GT3575R turbo.

 

Something different.

[Stumps 384]

Just thought I'd give an update on this one, went for 15x8 and 15x9 12 slotters with 225/60 and 265/60 rubber, came out looking better than I expected.

 

 

[bear351c 10,565]

Bloody beautiful car... 

[Stumps 384]

1 hour ago, bear351c said:

Bloody beautiful car... 

Thanks, been looking for a colour code 5 deep aqua XB for 28 years...after I crashed the v8 futura that I had as a stoopid stoopid teenager.

Wife finally let me get one, she's only a 250, but as we all know they can be made to go real hard.

 

the Vinyl roof has slight damage on the driver side near the chrome trim, so I'm weighing up wether to remove it and get the turret cleaned up or fork over and redo the vinyl.

[deankxf 21,501]

55 minutes ago, Stumps said:

she's only a 250, but as we all know they can be made to go real hard.

 

I was happy with the log 250 engine in My brothers XB 30yrs ago, it was improved by fitting a C4 trans over the BW35 he blew up,  and it still had a 2.92 diff. 

just had that off idle torque that seemed to get worse with every generation of falcon 6 right up to the AU and beyond probably. 

[Stumps 384]

this one pulls pretty good down low, it runs out of breath after 130km/h but still is pulling ok, havent had it flat out but I reckon it might hit 150ish if the road was long enough. Around town the 3 on a tree lets it down, first is useless above 20 and you spend most of your time swapping 2nd and third, I can't wait to get the 5 speed in it, still collecting parts to do the job properly.

[deankxf 21,501]

2 hours ago, Stumps said:

this one pulls pretty good down low, it runs out of breath after 130km/h but still is pulling ok, havent had it flat out but I reckon it might hit 150ish if the road was long enough. Around town the 3 on a tree lets it down, first is useless above 20 and you spend most of your time swapping 2nd and third, I can't wait to get the 5 speed in it, still collecting parts to do the job properly.

Yeah My brother had the 3 on the tree manual in a panel van XB for about a month or so until it jammed the gears up. ended up with a celica 5 speed which was nice until it blew up, and then fitted corona 4 speeds (cheaper at $50) and blew 2 of them up also.. then it got a 302/C4 combo. 
 
a single rail and 2.92 diff would be nice enough upgrade, but a T5 and 3.23/3.27 ish would be the perfect combo. 

130 is plenty fast enough for an XB on the street, cops will impound anything going faster these days at great expense. (My diesel gemini did over 140 i was told by the previous owner, he installed a CB to ask truckies if there was anything up the road as far as they could see before he took a run up from behind to go past them eventually getting to 140+ at times)

[CHESTNUTXE 7,739]

the xb with the v8 ratio t5 will work nice with 3.27 ,will not have to worry about putting strain on the box in 1st to get the thing up and going when putting your foot down ,the rest of the 2,3,4,5th are similar to the 6cyl t5,pretty sure the std 6cyl box has 3.25 1st gear,and v8 2.95,still a far cry from 2.46 1st close ratio single rail and top laoder.

[Stumps 384]

Pretty sure the first gear is 3.25, the ute was effortless in smoking the rears in 1st or 2nd and first ran out wayyyy to quick.

 

I could be wrong but I think the XG longreach had a 3.25 as the first gear...I'd have to find the service manual to check.

[bear351c 10,565]

On 6/30/2025 at 10:15 AM, Stumps said:

Thanks, been looking for a colour code 5 deep aqua XB for 28 years...after I crashed the v8 futura that I had as a stoopid stoopid teenager.

Wife finally let me get one, she's only a 250, but as we all know they can be made to go real hard.

 

the Vinyl roof has slight damage on the driver side near the chrome trim, so I'm weighing up wether to remove it and get the turret cleaned up or fork over and redo the vinyl.

 

I'd keep the vinyl roof, it's just awesome as it left the factory.  If you decide later on to spice it up with a Clevo, it all just slips in.....

[Stumps 384]

5 hours ago, bear351c said:

 

I'd keep the vinyl roof, it's just awesome as it left the factory.  If you decide later on to spice it up with a Clevo, it all just slips in.....

I must be getting old, sorta over V8's and the current exhaust sounds like a v8 so no point doing it just for the sound...hahaha

 

Gunna go 2v 250, I've got all the decals and badging to suit as well, maybe one day I'm might get hold of a clevo and drop in it.

 

Right now just want to get the XB's straight line performance close to my G6 (which is 228rwkw's according to Tunehouse racings dyno.). I'd be over the moon if I can get the XB to nudge a 13...

[bear351c 10,565]

Absolutely.!  250 2V is a good strong engine. Seen a few with triple Webers etc, that really blew my mind. You'll have to spend a bit of cash to get the old beast into the 13's, but its very do-able. Would look killer going down the strip all blue and 12 Slotters.....

[Stumps 384]

The current spec of the 2v I have sitting in the shed is 30 thou over 250 with a Speco 214@50 thou cam, the head has been cleaned up with over sized valves. Its been Balanced as far as I aware.

 

I have both the factory 2V and an Aussie 4V manifold to suit the head and pacemaker headers which will go into the dual 2.5 inch system the car already has.

 

I'm gunna get an electric dizzy and use a Streetfire module with it.

 

I'm not sure what to do about the induction side so Im open to any ideas.

1 hour ago, bear351c said:

Absolutely.!  250 2V is a good strong engine. Seen a few with triple Webers etc, that really blew my mind. You'll have to spend a bit of cash to get the old beast into the 13's, but its very do-able. Would look killer going down the strip all blue and 12 Slotters.....

I have thought about triples, it would be about the same cost as going efi, but would looks absolutly tits.

[CHESTNUTXE 7,739]

Yeah good ,the street fire is perfect,after months of changing timing on my old engine, just set it conservative in the beginning at around 24 or 26 or even 20 for easy start,then lay down a rubber road.

[Stumps 384]

Damn Days of thunder.....now I wanna color the rims black and turn the XB into a Nascar....

[CHESTNUTXE 7,739]

im dropping the hammer,no cole