SNIP Maybe it's the lockup converter he's thinking is 4th? Ken SNIP Actually I know it is! But it got your attention! In general that is what many of the newer electronic Automatics are doing, splitting gears by locking and un-locking the torque converter. Thus a 6 speed torque flite can be created. Call it what ever number you want by electronic controls and solenoids. You control the split by the looseness of the torque-converter. Of course with electronics, you precise control as to when. SNIP Quoting Tom Jennings < <mailto:tomj@xxxxxxx> tomj@xxxxxxx>: On Tue, 3 Oct 2006, John Elle wrote: I run a 4 speed 904! Where is this magical device you speak of! SNIP Change the spring tension of the valve that controls the pressure that the torque converter locks up at and you shift the miles per hour that it locks up at. I have mine so it locks up at 55 mph. There used to be kits available for this. In 1980 there were apparently two available torque Converters that you could have as stock, a low and a high stall unit. I picked the wrong one, the low stall unit when I had mine rebuilt, in the interest of fuel economy. Shortly I will purchase a 2000 rpm stall lock up torque converter and install it so there will be more affect. The high stall torque converter in my AMX has about 500 rpm of slip in it before it locks up which is a fair slip factor. (It locks up at the 39mph level) The Spirit will have more of an affect when I install the 2000 rpm stall lock up torque converter. Now if you want to get clever you can also control the slip by "Pulsing" the lock up thus varying the amount of slip you have. With electronics and transmission control computers you can do this. However slip and heat are related characters and with today's transmissions already doing a lot of this the lack of reliability is already a proven commodity. John _______________________________________________ AMC-List mailing list AMC-List@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list or go to http://www.amc-list.com