My 671 Turbine and GG1 work fine on 027 track in case you want to run a tighter circle (ie: smaller layout). That being said, I did convert over to the Lionel Fastrack due to the convenience that track offers. On old trains I find I always try to clean as much of the old oils and grease away as possible first, then re-lubricate using Lionel's recommendations as a "suggestion" as there are better lubricants out there today (you can do online searches and find most of the instructions for the trains you own, or similar one, which will give you maintenance information. In regard to the 671 you will need to take off the shell. Back in the day, that was just part and parcel of owning a train, being a little mechanical minded, so many today are not). DO NOT use 3 in 1. No no. I use sewing machine oil for all the locations Lionel says to use oil on and a molly based lubricant where they say to use grease. I've brought back to life some non-running engines from the 20's and 30's this way without anything more then a good cleaning and oiling. Of course on these real old ones once you get it running you find you need to fix other issues like wiring where the insulation has dried up and come off. I replace the insulation with shrink wrap tubing. Saves the original wiring and I only need to unhook one end of the wire to slide the tubing on helping to keep everything straight.