I think I have narrowed down the transmission I want for my 72 D200 with a 318. Because it is a ¾ ton truck and we do plan to use it as such I want a good transmission in it that will not fail on me like the tired stock one. Now my attention is on the torque converter. I know very little about automatics and even less about Mopar anything. So first question: What does lock up mean when dealing with torque converters? What is stall speed and how do I know what mine is? This truck has a 318 with 4:10 gears stuffed in the rear D60 what role does that information play in selecting the torque converter? This is the link to the trans I am 90% certain I am getting. http://www.summitracing.com/parts/TCI-111101/Application/?prefilter=1 This is the torque converter TCI said I need. http://www.summitracing.com/parts/TCI-142240/ What would happen if I used my stock original Torque converter? Other than voiding the warranty from TCI could I hurt anything else? Also, how do I know if anything is wrong with it to begin with? If the new Torque Convert does not have a drain plug, can I simply drill and tap the house to install one? Any input on what I have put out there so far?