supercharged holley carb?
 

Ive come a cross a holley 750 that was set up for being supercharged can it be used on a non supercharged 454 ?

yes was it indexed if so run the vacum lines to the intake and put in 6.5 power valves and check the jetting ,then enjoy

it was a 4150 #80557 never used whats indexed?

who ever had it might have had it indexed (boost referenced)
or look up part number an see if factory did it or send it to me I'll prep it for you for free and return next day FIXED ,just advise

Now thats and offer you can't refuse...