Help decoding a fender tag. I have a lot of it decoded but there are a few I cannot find. 1972 Duster 340.

This is what I think it reads

N42 R11 V6X V8X EN2
GF7 U J52 M21 N23 N41
GF7 31F6 419 442352
?55 D13 VS29 H2B 397921

Cannot find GF7 31F6 419 442352 ?55 H2B.