There are still two different styles for that year range. Up to 53 has a core that is currently reproduced and sold through many vendors and the 53-55 1st has a side "flap door" on the front and takes a slightly different core.
do you know the difference? is is mounting straps or core dimension differences?
I have about 10? of the flap versions and maybe 8 of the normal kind. most are blown apart though... wasnt aware off differences when I took them apart and assumed chevy was too cheap to have 2 different cores.
will carefully take apart both OEM kinds to see if I can figure it out if I dont hear from you-thanks
mark