As Carl posted, with other details:
That 53 Powerglide 235 engine came with hydraulic lifters and the 54 truck 235 engine had mechanical lifters, and, presumably, they had different cams?
The 53 Powerglide engine came with the older 2 bolt valve cover (used on all 216s and on 53 and on earlier 235s), and the 54 235 engine had the newer 4 screw valve cover.
The vacuum advance on a car 235 might have a different angle than unit used on the 54 truck 235?
