950 Ultra XP tuning on 500"

Several years ago I used to do quite a bit of dyno work with some guys running 358 Dirt Mods.
Some of the carbs those guys would show up with were really bad. Several were done by one of a few different self proclaimed carb gurus.
They were usually just totally out to lunch...... and often had issues that couldn’t be tuned out.
A few I tested had some variation of a spray bar type of booster.

But I think the worst ones were when the Demon line was first offered by BG.
Some of those things would literally hardly even run as they came ootb.
You’d know right off the bat....... it needed more than jets and air bleeds.
The owners would have been way ahead just pulling the motor off the dyno right there, selling the carb at a loss, and buying a new one from one of the successful carb suppliers for the series.
But...... that suggestion was never followed, so you’d spend all day chasing the tune around........ and in the end you’d have something that was mediocre at best.
If it was someone who was fairly serious about winning........ and this would be the same scenario if the carb was bought from the unknown-carb-builder, which would also end up making underwhelming power....... they’d run it a few weeks, and after they got tired having their *** handed to them...... they’d buy the “good” carb.
In the end, those guys would end up spending well over twice what it would have cost to just buy the good carb in the first place.

That’s the long version of...... there’s a lot of junk out there.