It doesnt matter whether you "Buy" anything or not. Facts is facts whether you like it or not.
Fact 1: Torque converters generate lots of heat from slippage.
Fact 2: Torque converters are designed to dissapate heat (During the non lockup time under 40 mph) This is your 100,000 cabs issue.
Fact 3: When lockup ocurrs, the converters pump and turbine are coupled resulting in no slippage. No slippage = no more heat. This is when the converter cools.
Now, lets unplug that lockup solenoid. What happens?? The pump and turbine are no longer coupled and the slipping begins. Well, who can drive 40 mph or less, not me. Get on the expressway, get up to 60, 70, 75.... With no more lockup, the converter clutch is slipping its life away at high speed. Since the converter is not designed to dissapate that much heat at one time it starts to balloon, then it turns blue, then it fails internally.
Now, Mr Ellis, if you still think I'm wrong here, I would love to hear it. I have been explaining this to you for some time now and I'm trying to put it as simple as I can since you are not a mechanic. Please make a point and back it up with a link or two for us to look at. I'm providing links for you to back up what I say.
Now, Twin turbo, I'll bet that HD 2500 had a HD cooling system in it which would definately help keep the converter cool.