Going to take a crack at Index racing next year

Since I'm running EFI it would be a pain to swap to a carb for index 1 week, then back to EFI the next, then back to carb, etc. Intake is too tall for a 1" restrictor plate. The plates are allowed but no electronics. I haven't been able to find any bolt type throttle stop for the 4500 size Throttle body.
Angle iron (obviously aluminum is preferred) off the rear drivers side tb hold down bolt, threaded hole, fine tread bolt and lock nut lined up with throttle linkage of carb/EFI.