I have an ati converter that stalls about 5000 on the t-brake N/A(about 500 rwhp)

If I add a 150 shot can anyone estimate what the converter will stall at on the t-brake

 

You wouldn't be spraying while its on the t-brake. Nothing will change. When you launch, the torque hit from the nitrous will probably flash the converter at least 500RPM higher than without the nitrous.

 

Typically a tighter converter is better suited for N20 use. That's not to say you can't use a big stall, it's just not optimal.

 

My 5000 turned into a 6000 with a 150 jet. 6000 wasn't TERRIBLE but with a 7000 shift point, It is innefficient. It only picks up 8mph in the first 1/8th and NONE on the top end, no joke. Also dropped .8 seconds, almost NONE in the first 60 feet, dead hooked. 1.58 on motor, 1.55 on spray. Tightening it up to 3800-4000 on motor so I can step up to 200-250hp jetting and still use the avaliable torque AT 5000, not well past 5000. Similar combo to yours. 396, small solid roller, 230cc heads, 3400lbs, 3.73. PG trans..

And while you can spray against the T-brake, it's not reccomended. It's unneccesary strain on the parts. Set it up to spray when the t-brake is released, or like me...with a WOT switch and I only go 50-75% on the T-brake, and WOT when launching.

It's worth trying out for fun and eventually doing a much tighter converter won't hrt you as bad as my combo because you have a 3 speed trans vs. my 2.. Goodluck!