04CTD, i have been running mine on Extreme for awhile now, for some reason i dont get into it as much as i did on performance or whatever, it is nice having it and so far my trans hasnt slipped other then rolling at 30mph and smoking and spinning tires for a 100 ft then the trans didnt like it. but i think you can drive it in extreme, but remember pay to play.

 

you would just really have to watch your tach and trany temps to know. I mean I can drive my truck in level 5 as well. I can just feel and see the tranny does not like it. I have alot of tire though. I bet on stock rubber it would just spin them forever out of the hole. in level 3 my truck just spins them. in level 5 there is just to much power and traction and it slips the tranny unless I roll out under boost. then the tires just melt. the reality is when there spinning your fine. it is in higher gear under load you have to watch for the slipage.

 

I can not get my 37s to spin anytime even on level 5 (except in 2wd out of the hole). But from a roll, no way. I do have 3.73s though....and I need more power/trans. Also, not sure what slip tc to go with when the time comes...89% or tighter?

 

yeah on the converter I would just listen to who you are buying from. they are the experts. when I was talking to them and they started geting into lever rations and max line pressures and things I relized they knew more than I did.

I am sure they can just give you a short little plus/minus list to going up to 91% coverter and then you can make the call.