[PGSigns]

Advertised stall speed is not always what you get. A convertor with a big block will stall more than the same one with a mild small block. So what they show them as is a ball park number. With a high performance engine with a big cam it may idle at 1200. For this engine it will need a convertor that is built a little looser so it acts like a stock convertor when stopped and not trying to stall the engine out. All out race convertors are not built at a specific stall speed but built to fit the entire combination of engine trans and car along with how the car will be raced. A 4000 stall convertor will act pretty normal with mild throttle inputs and can driven like a normal stock convertor. the vehicle will move when in gear and at idle if the brake is released. Now if you power brake it or use a trans brake it will allow the engine to rev a lot higher on the launch. Then there is the rpm a convertor will "flash" to and that is another thing that is tunable in a convertor. So it all comes down to for a stock engine they are not needed and when you build a evil engine it always best to call a convertor builder and get the one you need for what the plan is and not worry about the advertised stall.
Jimmy