You can use them on a 400, but minimal 104-110 octane straight. About 11.5 to 1 compression.
If done right, $900 is a good deal. #48's sell for 3-500 more than #13, 16 and 62's because they are RA III and 350 HO castings. All 4 castings flow similar.
If I were you, buy a set of rebuildable cores for $300-400 and build them yourself locally.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
