Day off today, so I've been doing some reading... Here is some relevant bits from the vintage off road nationals in the US:
(
http://vintageoffroadnationals.com/rules/ )
CLASSES
**All classes are limited to cars produced 1994 and earlier. Contact us for other approvals**
2wd Buggy
27 turn ROAR legal stock and 17.5 brushless motors only (under current rules).
Radio gear “electronics” are open.
Tires/wheels are open
Li-Po batteries are allowed.
Classic
Limited to “non-pro” and entry level cars (Tamiya Hornet, Mauri Ninja, Royal Ripper for example)
All 1/10 Buggies, 2wd or 4wd, 2ws or 4ws allowed
Handout Tamiya RS540 motors only
Radio gear “electronics” are open.
Tires/wheels are open (including narrow front tires)
Li-Po batteries are allowed.