Also, a lot of people say not to run the 5.0 kickdown lever......BUT if you run the widest band you can for 2nd gear, it's a good upgrade to do both. Doing one without the other is kinda a waste though. Again, JMO.
I would say it depends on the valve body and the line pressure he is planning to run. My tranzact valve body runs at 170 psi.
The recommended lever is 3.8 or 4.2. I know when I did the rebuild on my 47re in my diesel truck that initially I had the line pressure at 140 with a 4.2. The shifts were way to aggressive. Turning the line pressure down 15 pounds made the shifts firm but not aggressive.
Also in some applications the 5.0 lever aggravates shift overlap when the trans is in two gears at once just momentarily.
My current 904 build with aluminum front drum and the widest band available 1.75 inches I am going with a 3.8 for a clean shift. More is not always better with the levers. Just mho.
