You need to post a pic of the heater to get an answer on that. There were 2 dealer offered heaters and dozens of aftermarket heaters in 1954.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.