Engine size plays a role too. Some narrow powerband engines would want less and a larger engine may want more to use the torque. Normally 1000 is the "Norm"

 

There's what you think would be right and what actually works. Nothing is carved in stone on this subject and here's a quick example. A car in which I was involved with had a converter that dropped 200rpm at best, from 7400 to 7200. This is a big cube aspirated combination. I figured it may be better to use the torque this motor can produce down low so I tightened the converter by 400 rpm. Car sounded better, could hear the shift change and I thought it would come around with a bit of tuning as the increased load changed the A/F ratios quite a bit. Car was a slug. Lost almost a tenth and 9mph in the 1/4. Fought it all last season as I don't give up easily.

Just an example.


Hutch

 

Sorry I should be been more clear, I'm only referring to turbo vehicles.

 

My turbo ls motor/converter only drops ~500 rpm shifting at 6k and runs great to me...
Last 3 years or so I've been setting the shift light at 5500 and it would drop 7-800 rpm. New converter this year and first 2 passes it didn't even drop enough to turn the light off.

Turned it up to 6k at the next track outing and it drops to just 5500 and picked up ~6 mph

Like said...general rule, then whatever works. I was pissed and thought converter guy messed up and made it way to lose at first, I'm a happy man now