Help Identify This 340

Take some sand paper and wipe away paint grime under driver side right under deck seam to Right of timing chain There is a very light stamping there. 69 340 big valve, score! 6 at end of 340-6 means nothing.
ok here we go i'm 80% sure on the numbers...all three 3's in the serial were sort of worn, but i'm pretty sure they are indeed 3's

EW 340 P28330089