I installed new wires on my 90 this summer . really wasn't all that bad, just a couple of scrapes and cuts. take them out as an assembly , one side at a time. Lay them out and match the wire lenght , replace one wire at a time . Draw a picture of the way the wires are on the cap, makes it easier than tracing later . about an hr on the drivers side and hr and a half on the pas. side. I did buy new clips for down near the heads they get brittle. If you haven't ever installed plugs , a section of the passanger side fenderwell can be removed to make it much easier to get at. The section around the back. About 10 screws there are two or three in from the bottom .Removing it makes life much easier . Have fun .