If your film was stored well, you should be OK.
I don't know the relation to FP4 but I recently shot some Ilford Mk. V film tested in '73 (expired '79 at least), did a test roll and liked the results shot at 200 the most, but EI of 400 was not bad by any means. I developed it in HC110 (1+49) for 8 minutes, which is what I have been doing basically everything from Tri-X to PanF+ 50 at, and I've been very happy with it.
The Mk. V was reportedly a cine film rated at 400, so it may be similar in technology.