Better remove the cat if you have any unburned hydrocarbons going down the pipe whether oil or from a misfire.

Get some 1984 300zx wheels, they bolt right on but you will probably have to run 205/60s or 215/55s or they will rub with as mine do a bit with 215/60s.

 

I will probably inspect the cat once the car is ready for daily driving.

I'm planning on doing work on the existing wheels to get them in good shape. There's a little rust on them but I'm going to sand them down and treat them to see how deep it goes. It appears to just be surface rust though.