Here's how to do an "at the track" rocker arm geometry setup. This means without the time or tools to do it exactly right, but get close enough to get back in the race. Imagine you'd broken a rocker or shaft and had to slap on a set of rocker parts you'd never set up for, or someone gave you.
I've always wondered why some enterprising company doesn't sell precut and pretipped pushrods in millimeter steps! I'd carry a few sets of those to the track.
First, with whatever push rods you have, bolt on the replacement parts with no shims, but with the valve adjusting screws backed all the way out.
You'll probably find that even with the adjusting screws backed all the way out, you can't get the rocker arms seated all the way down on the cylinders with valves open.
At least you tried. Unbolt the rockers and shim the rockers. If you can't get proper shims, scrounge up some machined-flat washers that are all the same thickness.
Usually, shimmed up, the rocker arms will fully bolt down. If you're very lucky, you can even adjust the valves. The warning signs are running out of threads as you back out the adjuster screws. Be careful to notice on swivel feet adjusters that you're not trying to pop off the swivel foot itself as you unscrew the adjuster. When you hit resistance, stop.
Some swivel foot adjusters allow for more back-out space than others. I've learned to carry a couple of sets of adjusters made by different manufacturers.
If you can't make a swivel foot work, try a standard adjuster. If no adjusters work, shim the rockers out a little more until they do.
Okay. Adjust the valves slowly, watching and feeling for valve spring bind as you do. You'll feel it if it happens. The rocker arm will be pushing so far down on the valve spring that the whole spring is compressed, the coil turns impacted down on each other. The crankshaft will resist your effort to rotate it.
If you force the turning, you'll either break or bend a rocker arm, or damage the spring and/or valve retainer.
Binding means that even with some adjustment having been possible, you still don't have enough slack space in the valve train, and you have to reshim.
If you had no binding, and the valves adjusted out okay, get a mirror so you can see the angle at which each valve adjuster is striking the valve stem.
If the adjuster is just barely touching on one side of the stem (meaning the extreme here, since adjusters should strike the stem off center), you have really bad alignment and have to relocate the rocker arm lateral position on the shaft by shimming it.
Porsche (in the 4-cyl 356 days) had the valve adjusting screw opposite of our VW arrangement. Porsche put the screw against the pushrod rather than the valve stem itself. Scat makes a set of rockers like this, and they are much better because that arrangement better tolerates valve train geometry errors.
Swivel feet themselves, introduced on the Porsche 911, allow for a certain amount of error. VW took the purist route and made us work harder, presuming VW mechanics would always show up for work sober and fully dressed.
If you were able to get to the point that you've slapped on a different set of rockers, and they adjusted okay, and the engine runs, you probably still have valve train geometry error, but obviously not so much to keep you off the road.
At this point, the most common form of error is not getting enough valve lift. You're going to be down on power from a properly set up valve train.