Vortech idler pulley 6rib to 8rib

[hollowdweller]

Is this the correct pulley for the mounting bracket when switching from 6rib to 8rib?
Vortech 3.0 Smooth Steel Idler Pulley (8-Rib) [V4FL016-170] - $34.00 : SuperchargersOnline, Worlds largest Supercharger Resource. Get Serious About Power

this is the 6rib one:
Vortech 6-Rib Smooth Plastic Idler Pulley with Lip (3) [V4FH016-150] - $34.00 : SuperchargersOnline, Worlds largest Supercharger Resource. Get Serious About Power