ATS experience
I installed the ATS converter and valve body to my otherwise stock transmission in March of 2002 after experiencing lockup clutch slippage with an injector upgrade. We upgraded to a bigger and heavier 5th wheel at that time too and I could tell the stock converter would soon be toast if I didn't do something soon. My installation was done by a local transmission shop who had never worked with ATS before. The installation went well and I am very happy with the results. The lockup is so rock solid now after the ATS converter was installed that I also added an Edge Comp box and EGT & boost gages.
Once on the highway I run about 65-68 @1900 rpm approx (3. 54 axle). It seems to be pretty happy there. I vary between letting it lock up when it wants to and using my mystery switch. If I use the lockup switch, it is usually in 3rd gear when running in town or at slower speeds or to force the transmission to shift 3rd to 4th while locked up. When I do shift locked up between 3rd & 4th, I usually let off the throttle a bit until after the shift is complete just to give the transmission a break. I feel quite strongly that even though the transmission is really solid now, you will reap rewards in terms of length of service and reliability in not pushing it harder than you have to.
In my opinion, if you have an automatic, even if you have no upgrades, the upgrade to the converter and valve body is the single best improvement you can make... ..... drivability, lower operating temperatures, more power, better shifting, more trouble-free miles... ... ... ... ...