I'm fortunate that I have a good friend who is a really first rate automatic transmission technician, I seldom run an automatic on the street but when I do I take all my engine specs to Jim, he calls the torque converter shop he does business with and gets one built to match the engine pieces! A 2000 advertised stall converter behind one engine can actually stall at 1500 rpm, but on an engine with a different cam, heads, compression ratio, quench, etc. it might not "hook" until 3,000 rpm.