I'm using a 250 truck 2-groove damper on my 292 Nova, so far so good but I don't plan on turning it over 5000.
I do have a giant truck 3-groove 292 damper (in fact IIRC it is from a van!), painted nice fresh Chev orange, weighs about a ton, cant use it because its too long to fit in the Nova (even if I used an electric fan). I can sell that to free up space as it is pretty much just a display item for me, wont fit early Novas.
I don't remember any timing pointer issues swapping dampers or into the 292 but those could vary by year. As stroker noted, you should always find TDC and degree/check the damper yourself, new or used, so you know where you are.
