Hi all I just visited the B&M website to get more info on the megashifter http://www.bmracing.com , its says its also compatible whit the 4L60E transmissions but whit this NOTE " fits 4L60E & 4L80E with used with custom installation where an aftermarket controller is used to command the transmission".

What is that aftermarket controller and where I can buy it, also do I get the truck Megashifter or the basic one?

By the way its a Blazer 1994 (old box style) 4.3 ,4x2.