I have a 350 30 over, vortec heads 489 lift cam, it also has a 373 rear

Need to install a torque and going to do a shift and servo upgrade

Need advice on what stall to use, i was thinking 3200

The 2 most important factors for choosing a converter are the cam duration at 0.050" and the cam lobe separation angle. Without those, it's all bad guesswork.

are you TPI or Carb?

For best performance, the converter needs to match the cam grind. Doesn't matter what else is done to the car. They all compliment the cam and converter. If the cam doesn't match the rest of the components then it's a bad cam grind choice.

It's real easy to mismatch components and they'll work just fine together up to a point however you're making an investment in parts and you should be trying to make everything work at their peak efficiency.

It's no different than saying you want to run x.xx gear set without considering driving style, engine rpm range or tire height first. Something like 4.10 gears with a 700R4 and 26" tall tires will be fun from stoplight to stoplight but would really suck on the highway.

As for converter stall speed, if you have a cam card, it should show an RPM range of the cam. For street/strip, you want a converter that stalls around 500 rpm into the powerband. For full race, a minimum of 1000 rpm into the powerband is better. Too high a stall speed can be just as bad as too low. The stall speed is to get the engine into it's powerband as quick as possible for best performance.

If your cam card says the cam starts making power at 2500 rpm then you want a converter that stalls around 3000 rpm. Plus or minus a couple of hundred rpm either way will still work. For street use. it's better to error on the lower end.