The stall ratings on convertors are kind of like saying "it's blue" when you look at a blue car. Which blue can be unique to that specific car. In that respect, a convertor is so affected by the engine and the package, that in most cases, the stall will change from vehicle to vehicle unless they are compeltely identical cars. The brake stall is the speed the convertor lets the engine reach when floored and the output shaft is held still in 1st gear. This is typically lower than the flash stall. This is also what a lot of convertors advertised stalls are. The other is flash. Which is the same thing, max engine speed, but without the outputshaft held, and in high gear. Teh way to find it is cruise at lower speed/rpm than you think it is in drive (3rd gear). I use around 20-25mph in high. Then floor it. This is not easy as if you floor it in a typical auto, it downshifts and that will not read right. So give it enough throttle to bring the engine up i power but no downshift.
The part about low vacuum and that cam, vs idle rpm, is why i asked about cylinder pressures. Vacuum has nothing to do with how much power the engine is making at idle. Most performance engines can idle as low as 400rpm. But not well. I dont call anything over 900 idle, as for the most part, you are off the idle circuit in the carb by that point in the throttle opening.
