My 78 pick up had 3.55. My guess is so did yours.
Right now my old 88 D350 has a LA roller cam 318.Had to replace the blown 360 when I bought it.
How many miles is on it is anybodies guess. The guy I got it from couldn't remember as the rust bucket 85 Dodge Diplomat was parted out many years before I got the call "It's sitting under a tree where I pulled it.Come and get it."