Yes for some resson 1962 was the only year Chevrolet put the torsion bar sup. under the c 30 and c 40 in 1963 they went back to a straight axle the dry weight of a 453 is not much more than a 283 so i thought that the front end could hold it

1947 1Ton stepside
1962 K20 Fleetside
1962 C40 12' flatbed
1963 C10 Stepside
1963 C20 Fleetside
1965 C10 Stepside (Daily Driver)
1973 C20 Stepside fire truck
1973 C50 Utility truck Houston Power & Light