There was no HEI designed for a 1954 235. I looked up NAPA 481692 and saw a pic of an HEI designed for '70s GM vehicles. It can be modified to fit a 235 but is not going to fit right out of the box.

"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.