The 268 H is a very good cam for that 402. There are factors that need to be known, though. Most importantly the compression ratio. Do you know what the combustion chamber volume is??? What heads are you using?
THe 268H can stand some compression, up to about the low 9:1 area. Just make sure it is NOT the 268h XE cam, do not, do not, use the XE cam!!!
Torque converters have evolved a bunch, especially in the last 10 years, and continue to do so!!!
A torque converter made specifically to match your car/engine is the best performance improvement a person can make. The good ones cost money, though...
Cliff Ruggles, the Quadrajet "go-to" guy sells converters made for street driven vehicles. He doesn't manufacture them, he does sell them. A converter that is not loose on the street, but provides the "WOW" factor when you hammer the throttle, is a awesome thing!!!
www.cliffshighperformance.com