You will need a throttle kick-down solenoid and an unloader valve for the pump but be warned these can be a bugger to set up properly. You can use a centrifugal clutch in place of the unloader but honestly the unloader does not cost a lot and works a heck of a lot better than a clutch, which IMO don't work well at all on a compressor. If you are considering just a single stage reed valve pump then a clutch may be your only real option but that setup on only 6 1/2 HP is not going to produce a lot of air.
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