I tried to change the bolt pattern on my Volvo 1800E 40 years ago from 5x4.25" to 5x4.5" by having the lug holes welded up and the new bolt pattern drilled into my steel front hub and solid rear axle flanges. Unfortunately the machine shop couldn't place the holes in an accurate round circle and they had to shave .05" off of the radius (.10" total diameter) of the shoulder style lug nuts to get them to fit. Needless to say, the wheels are super off center and the shaking is awful.
Instead of shipping everything off to DutchmanAxles.com and start over, I was wondering if it would just be easier to get some used or new Ford Mustang bolt on front hubs and machine off everything else except the wheel flange and then machine the center hole to match a new machined lip on the back sides of my Volvo axle and hub to center them? So, mount the Mustang flanges with wheel studs behind the Volvo flanges with the wheel studs poking through.
The holes for the Volvo studs are a giant 5/8" and I don't think that I can get 3" studs that would fit them anyway. The photos of the Volvo axle and hub are non molested stock spares.
If this where a solution, what should the tolerance between the outer hole and the inner flange be for a (snug) fit?
My 2 decimal place HF digital caliper's battery just died so I don't know what the back of the hubs and axles diameter are. The Volvo flanges are something like .35x" thick. It's amazing just how worthless only 2 decimal places are.
Also, these are the front hubs with vented disk brakes that I want to adapt to my control arms and the rear axle out of the Volvo 164 that I already have on the 1800. I think that the 1031 rear axle is basically a Dana 44 axle with it's axle tubes, outer bearing housings, shafts, and press on bearings with a Dana 35 7-5/8" R&P
It already sounds like too much work just talking about it, but after everything is perfect, just tack weld the Mustang flanges to the Volvo hubs and axles?
Kind of a reverse wheel adapter/spacer. 
The earlier Volvo 1800 and 122 Amazons were 4.5" bolt pattern and will bolt on your existing hubs.
In reply to tester (Forum Supporter) :
Thanks, I forgot that volvoclearinghouse put vented 240? front disks onto his 1800ES and will have to reread it tonight although I don't remember the wheel bolt pattern. I had always wanted to replace the complete front suspension and crossmember with a 164's but I'm running out of time plus I probably can barely crawl out and get up from under the car anymore.
The bolt on solution in the front is a hub and rotor from a 122s made after 1963, they are 5X4.5 and fit your calipers. The rear is a different problem. I am sure someone in Sweden has done it, but I have not.
In reply to TurnerX19 :
Sounds great, thanks. Anybody know the stud knurl diameter and if ARP sells a 3" or so long one?
Dorman lists one for 1973 140 on up with a knurl diameter of 0.643" which I'm sure fits the newer 1800 with the crappy 4.25" bolt pattern. Also early Dodge Vans.
DormanProducts.com: 1/2-20 Serrated Wheel Stud - .640 In. Knurl, 1-5/8 In. Length
Jegs seems to indicate that their widest stud knurl diameter is .625".
Well, I found a photo showing that someone found some 3" studs that fit in a front Volvo hub. Since he put a Ford 9" rear end in the back I would have to say he has 5x4.5" bolt pattern but I can't say for sure. I will have to dig deeper and maybe try and reach out to the builder. The web page link is from 2007 and of a 1971 1800 with V8 engine.
build pitures summer 2007 Photo Gallery by james richardson at pbase.com
I keep seeing this hub/rotor assembly on the internet, this one form IPD.com. Is it what the early 5x4.5" bolt pattern hub looks like? Is this a two piece unit and if so, how is the rotor held onto the hub?
Well, looks like I would need a 4" wheel stud to make this works. Probably need one even without the Mustang hub. Bummer, the nice thing about the Mustang hub is that it's a wear item and I could get them for free and have the machine work done locally. This would also have been the solution for the rear axles as well.
Please note that I have guessed at some of the dimensions such as the true thickness of the hubs and brake disk and the Weld nut's washer. Still pretty close for discussion. I should just get some all thread...
