I've got H4 headlights fitted with parking lamps in my 1950 truck too, they work very well. Mine dip to the "wrong" side of the road as well.

Stuart.

1950 Chevrolet 3100 (occasionally working) truck:https://c2.staticflickr.com/6/5490/30684982201_6dc479d18d_c.jpg
1928 Chevrolet AB National Phaeton: https://c4.staticflickr.com/6/5573/30137792083_42886d30a4_c.jpg
1932 Austin Special Sports: https://c8.staticflickr.com/6/5793/30116567183_1520e67c4d_z.jpg