I believe the OEM tire size for your Eldo was P235/60/16, correct?chris203 said:
If so, the overall tire and rim height for that setup would be 27.235"
Using that number for speedometer calibration, here are some quick #'s...
P255/35/20 = 27.112" overall tire and rim height
P235/40/20 = 27.490" overall tire and rim height
P225/40/20 = 27.171" overall tire and rim height
I think any of these would work well for you since the total height is +/- .25". The P225/40/20 is only .064" short of OEM specs. If anything your speedo would read slightly slow, but I doubt it would be noticeable. I'd use these sizes as a starting point to see which will be the most economical choice for your rim width. They might not all be available or in production, so having some options should help.