No they re too short for 250/400 NT. They need to be 397mm. Thats what my 1980 Ohlins catalogue lists but often the Ohlins fitments were a little longer. Eg for the PE they had 409mm but stock is 400mm. Off the top of my head the RM shocks are a few mm less than 397mm, 394 or 395?? I got a stock set so could check. In any case 385 is too short for the 79/80.