Thats a pretty ridiculous thing to say - I'd love to see some evedence to support it.
There is claim (originating from period advertising from Nissan) that there were 50 consecutive "wins" in period for for PGC10 (sedan) and KPGC10 (Coupe) racers, however these are spread accross different series, classers and sacnctioning bodies, very few of the "victories" actually ammount to outright race wins.
There's no doubting though that the Skyline was king of the hill for an extended period in whatever class it was raced and often competed, and sometimes beat more exotic machinery racing in the GT classes above.
I've very limited knowledge of the success the KPG10's had, but know the 32GTR was banned from competition in Australia, as it whooped the collective asses of the Holdens and Fords of the day (Y)