Further, just to lay it out...
Bore centre - 70/71mm diameter
Bolt pattern - 5 x 4.5" (which is 114.3mm)
Backspace - depends, but in context my 7" rim has a 3.75" backspace and my 8" rim has a 4" backspace. For offsets there are loads of sites that will assist you in turning one into the other.
The alternative is to plug your car into Summit or Jegs and search for wheels that fit according to them. That way you can easily find out bolt patterns and hub centre bores. Offset and backspace will depend on the rim specifically as they're not all the same. And your car of course. Perhaps danv can help as he's got a 70 and has done a few wheel swaps over the years if I recall correctly.
Those wheels will fit fine..As was stated above the Cragar S/S wheel locates off the wheel studs and uses mag wheel lugnuts. Note there are different length shanks on those lugnuts, get the correct length and all will be good. The wheel dealer will know which length lugnuts you need.I think you'll find that those particular Cragars are a truck rim, which may explain the larger hub centre diameter. Could be wrong, but they look that way.
If you go for them, I know a local engineering mob who can machine you up spacers. Although with the rim being steel, there wouldn't be much "meat" to support such a spacer.
As for whether they come with a smaller centre bore, I think you'd have to ask Cragar.
A 255/60 looks nice, I think a 275 would be safe, but theres gonna be a pretty big sidewall bulge. 295/50 will work on an 8" rim.Thankyou all so much for the info.
Im wondering what is the widest tyre that can be safely fitted to 7". I keep getting different answers from people.
Some say 235 fits, some dont.
Aftermarket wheels are universal so the center bores are big to accommodate several different vehicles. That being said most aftermarket wheels are lug-centric meaning they rely on the wheel studs for centering. The fact that a wheel is hub centric has nothing to do with load bearing, it is simply for centering purposes. It is always the clamping force (created by the wheel lug torque) that supports the load. There are hub-centric rings available from Coyote, Excalibur, etc but these are more tailored to late model vehicles. Haven't ever seen one for a Cragar application, especially on a vintage car. I'm sure they could be machined if desired though. Older vehicles seem way less sensitive to vibration than the tin can econoboxes of today that transmit every irregularity to the driver.If it's these wheels you are after in the link here.....
Cragar 3305712 - Cragar Chrome Super Spoke Wheels - Overview - SummitRacing.com
....then I don't think you'll have too much of a problem.
Firstly, the prices is very good compared to what we have down here.
Secondly, they will look pretty good, especially compared to your black paint.
Thirdly, I believe there are two types of load bearing fitments. One is on the studs, and the other is on the hubs. By looking at the specs of the wheels, I believe these are the stud type because it says they are not hub centric, so to me it means that the studs will locate and take the weight of the car. If they were hub centric then it would say so.
Even if I am wrong in my interpretation, I would reckon that most of the cars out there today with aftermarket wheels would be using wheels with larger center holes than what the hubs are. Two of my cars are, and I have never had a problem.