Can you try your biggest flanges on some Peco code 75 track?
Track lasts a long time, better to change the wheels and lock more realistic track into your future.
Mark in Research
I run quite a few old Lima locos on Code 75. All Australia stuff such as VR B Class, S Class, NSWGR 44 classe etc. I did run a Lima XPT until I bought a properone.
No problems running on the actual track. It's the points and crossovers where I have a problem. It's the width of the wheels. They short out the points/frogs of both points and crossovers. The little plastic "pointy bit" isn't wide enough, and you get a short to the other rail because of the WIDTH of the loco wheels.
Solved it with a tiny dab of clear nail varnish to "extend" the plactic bit along the rail a bit. Have to renew it every now and then, but worked well.
Next was the poor pickup on Lima locos. The wheelbase of most of the bogies is EXACTLY the same distance as the rails between cross overs and they will stall. Only way to fix that was to add extra pickups on the non pick wheels. To solve this even further I usually run a trailing van behind the loco with pickups on the trailing van's wheels, wired through to the loco.
I also bashed-up my Lima locos with flushglaze windows, replacement pilots, kadee couplers, and LEDs and fbire optics for the headlight and drilled-out marker lights. A Bacis TCS decoder with back-EMF will run an old Lima pancake motor quite well.Lima loco here
Hope this helps.