You don't want the steering system to use the internal stops inside the steering box.

Use the axle stop nuts.
You can trim these shorter if needed to gain a sharper turn, but let the stop nuts do the stopping.

Vega boxes - and I'm sure others - will be damaged by using the internal stops.

Fwiw, a stainless Chevy mag lugnut makes a great stop nut.
You'll have to trim it down a touch, but that's easy.
They're 7/16-NF as are the kingpin lock/stop bolt threads.

The Vega box is about 4 1/4 turns lock to lock and the pitman arm is 6" long.
I have a 5" long pitman arm and while some may perceive the steering to be too slow, it's not.
Parking is quite easy as well.

Granted, the Vega is a cross steer setup, but the pitman arm lengths and steering arm lengths could be duplicated on a fore & aft draglink setup like yours without too much trouble.

Keep n mind, you can still make changes after the car is up and running.