Ideas on Throttle Lever for Engine Run Stand?

I ran a 292 in my 55 Ford "Street Stock" stock car it had Thunderbird valve covers but was really out of a junkyard dump truck! I was 17 then in 71 I have that same Supercharger here now but only the blower nothing else.

 

On my friend's dyno he wanted something to hold the throttle at any position while he was outside of the room, so I wired two relays together as you would for power windows and hooked it to a linear actuator. Just wire each relay ground at rest, postive switch and trigger it with toggle switch. You can hold any position hands free and all you need are two longer wires to be as far as you choose away from the stand.