Looking at new wheels!(need offset help)

[cursed87]

pages.ebay.com/link/?nav=item.view&id=400756223313&alt=web

I found these wheels and I'm dying to have them on my car.....
In the past I just found used rims that I thought "fit".
I have never went very deep into hub bore and offset's. I find myself trying to take the "safe" route with my classic. I have had to many issues in the past,and just wanna do it right the first time!
Now I have read countless thread's that talk about offsets and hub bores,but I'll admit that I get a little lost..haha..
So here I am asking for help or someone to "shine light" on this before I jump into it..
These are the specs:
Size: 20x8.5
Load: 2100lbs
Finish: Gun metal with machined lip
Offset: +20mm
Back spacing: 5.54"
Hub bore: 83mm

Now here's the reason I bring this up..I know our cars are 5x115! I found these EXACT spec wheels just under $40 a piece in the 5x114.3 bolt pattern
Now I KNOW the stress put on the lugs here,and I am not saying I'm wanting to buy these n slap them on(thought about it, I admit)
My question is how much more offset can I go with these? Because if the spacer's needed to achieve the right stance is the same as adapter's I can save some money here. These wheels won't be able to be installed anytime soon as I have to buy one at a time then tires and so forth,so I'm "planning ahead"..
I found some 5x115 to 5x114.3 adapter's that have:
Width:32mm
Center bore:74mm

So what center bore do I need to start off with? Do I need to find adapters OR spacer's that have 2 dif bores to fit our hubs AND the rim? I'm lost..haha
There are also the same rims with +10mm or +35mm offsets that are 5x115 but I brought up the 20mm off set to "compare" how much room I have for adapters or just run spacer's. I want them to sit flush with the wheel well,if they poke out a little I don't mind! Just not too much. I ALMOST ordered one wheel last night to get the show on the road,but thought I'd better get some advice! I've never bought new wheels before so this is all new to me.

In the past iv ran mustang gt rims on a Buick lesabre before I got 18s. I do know the 114.3 and 115 differences but never had a issue with the mustang wheels or the aftermarket's. BUT I did have some universal 16s off a old vehicle that I ended up putting on the Aurora for a short time,I did have some shake but I also think the tires where off balance.
Anyways, any input would be greatly appreciated!!! Thank you for taking your time to read this!!-Chris

[sall]

Using 5x114.3 on the 5x115 is really not worth shearing the lug studs IMO.

Factory hub bore is 70.3mm. You need 70.3mm or larger. If using larger you will need hubcentric rings to knock down a hypothetical 78mm bore to 70.3.

As for offset anything between +35 and +51mm(factory) is safe. A +20mm offset simply will not work unless you run a really skinny tire. You will have the tires sticking out of the fenders which looks bad and they will rub.

I am running 20x8.5" wheels with 255/35-20 tires. Front offset right now is +45 and rear offset is +32 with a 1" custom drop. I have 10mm spacers for the front to bring it to +35 but not until my big brake/suspension upgrade is finished.

There are plenty of wheel and tire calculators out there to compare. I like this one: www.rimsntires.com/specspro.jsp If running 255s I wouldn't go anymore than +35mm front and +32mm rear. You can get about an inch further out than the stock setup 16x7 with 235/60-16

So in summation just buy the 5x115 +38mm version of those wheels you like and throw some 255/35/20s on 'em. You will be very similar to my setup just a few mm further in wheel well.

[cursed87]

Thank you so much! That helped me understand greatly!
Knowing all of this I am searching online rim store's to compare now! I found charger or challenger replica wheels for $50 cheaper. The bad part is it doesn't show the hub bore or offset.. These wheels I brought up are my favorite hands down,so we'll see!

So what your saying is the +38mm offset wheels will be fine w/o spacer's,but I do need hub centric's to accommodate correct?
The lower the offset the more they "poke out" so to speak?

Also my buddy has brought to my attention the following:
How much does it effect the speedometer?shift points?alignment issues?do I need to get the speedo and tranny programmed to recognize the difference?

I'm not a fan of skinny tires so I took note of the tire size you are currently running.. BTW beautiful stance...well wheels period!!!

[sall]

No problem. The calculators go a long way in helping understand.


The lower the + offset the more they will 'poke' out, yes.

If you use 255/35-20s the overall tire height will be 0.1" shorter than stock(the calc will break all this down for you). When speedometer reads 60mph (96.6km/h) actual speed will be 59.8mph (96.3km/h): 0.3% slower. So, not a noticeable enough difference to cause speedo or ABS issues. I have had no issues with any of the aforementioned. I have seen at least one Riviera running 265/35-20s. Which would be identical to my rear offset at 1.1" poke from factory with a +38mm offset, but too wide for the front. Staggering tire sizes would probably confuse the PCM and require reprogramming. 255/35/20 vs 265/30/20 is 0.3" difference. I'm not exactly sure those wheels you looked at come in +38 in that finish though. I saw all chrome.

You won't need spacers unless you want to push them out further to max it out for flushness, which is what I did. I would recommend getting hubcentric rings though if the hub bore is not 70.3mm. This will help prevent vibration and let the rims ride on the hub rather than the lug studs how it is supposed to. Which is why 5x114.3 and hubcentric rings is terrible idea! Aluminum hubcentric rings are pretty inexpensive anyways and may even come with your new wheels if you ask.

If you find some 114.3s you'll have to pick one with an appropriate offset to allow for the conversion adapters extra width. HTH.

Thanks. I picked those wheels because... chrome, five spoke and they some what resemble the Olds rocket emblem. An homage considering I have no badges or script. I like subtleties like that. Quite a bit of custom work in/on my '96.

[cursed87]

Yes they come in +10..+12..+20..+32..+38mm in the finish I brought up..The chrome one's are beautiful but I'm going for the "sporty" look over "luxury"! So they are to much IMO for the desired look I want to achieve.

pages.ebay.com/link/?nav=item.view&id=400877926744&alt=web

These are the challenger replica's I also brought up,but they aren't exactly comparable to the gun metal ones IMO.. Plus the offset is +20mm which from what I understand is too much for the classic..

With the options in mind which would be best to be flush...+32 or +38?

And man, close up picture's of those wheel's almost made me drool haha. Not really but that close up does make so much sense with the "rocket badge". I really like the way you chose them!

I also de-badged mine shortly after I bought it.. Going with the A rear window decal was a change for me,but I wanted a large decal. Originally I wanted the "db drive logo" (my audio system).. For one I have a Orion HCCA competition 15" I'm considering to install. That would kinda be tacky IMO. Also I didn't wanna attract thieves by advertising.. So I went with the A..

Btw off topic here....but have you built front LED side marker's and sold them to anyone interested? Years ago I emailed someone about getting some made..haha

Anyways, I can't say thank you enough! -Chris

[sall]

+35 is the closest I would go. Since that is not an option +32 on the front with 255s is pushing it and would probably rub. +38 would be the safest bet and you can always add small spacers if you want to flush it out more.

Yeah it is not something most would notice but a nice subtlety!

Haha being loud is enough an advertisement but you literally can't get my system out. Someone would have to destroy it for satisfaction of not being able to steal it. I want to get an AURORA script CHMSL overlay though.

Yes, my entire '96 is all custom LED. May have been me you emailed. Most of my stuff is on youtube. Hit me up and we can discuss via PM if you want.