Welcome to the forum Jeff. Your Mustang seems to be in great shape. Any photo of your 1970 coupe?
About your wheels problem I am afraid you don't have much choice with the 4 bolt pattern and there is not a chance you can get any 5 spoke wheels with 4 bolt drums.
Here is some 4 lug wheels for classic Mustangs here: CJ Pony Parts.
There is also a company selling custom conversion kits allowing you to install 5 lug rims. You may want to contact them:
The problem is that it will push your wheels out and you might be limited in tire size.
The other solution is to convert to a V8 spindle and brake setup but that won't be cheap if you have to get all new parts. I am not sure what you would need to replace on the rear but it might be the entire rear end.
:-) Thanks for the response Thierry, as I suspected without total replacement of the hubs & axels with 5 bolts my options are extremely limited.
I would opt for the adapters but that would seem to create yet other problems, and I once had a set on a '67 Fairlane I owned, and had trouble with them staying torqued all the time, lost a wheel a couple times..That's no good! And they would often rub the wells to.
As for pics of my '70 Standard coupe I lost those a few years back , bought the car for $150 in 1976 as a restorer from a bridge collision, I subsequently sold it after restoring it for a break even amount after parts of $2400..The best & first Mustang I ever had, and wish I still had.
But this '65 is going to be even better after I get R' done, older and wiser and more finances to put into it helps.
Thanks again for the ideas.