I am assuming that the '54 is similar to the earlier AD pickups. Most will cut out the top lateral part of the radiator crossmember and mount a chevy radiator in front of the crossmember. This will work but you greatly weaken the crossmember. I used this method in my '48. In time, the top bar of the grill will crack. There is a better way. Get a GMC radiator and radiator crossmember. Cut both your chevy crossmember and the gmc crossmember about 1/3 way up. Take the top of the gmc crossmember and the bottom of the chevy crossmember and weld together. This will get you the radiator in the right spot without compromising structural rigidity. You will have to slightly trim the hood latch panel. If I recall correctly, the ears which go out to the fenders may have to be redrilled. Shoot me your email and I'll send you some pics.
