I don't have all the info needed but maybe someone could help me. I have a '06 rcsb Silverado 4.8, 70mm turbo, 3.23 gears and a 315/60r15 tire. I had a 3800-4000 stall in my 4l60e but I'm now installing a 4l80e and would like to know what stall speed I should go with. With the 60e my rpm would never drop below 6k wot shifting and wouldn't shift into 3rd until 95mph. I might switch to a 3.73 gear and 78mm turbo in the near future. I'm thinking about a 3600 stall would be decent.? I will be installing the 80e with the stock converter at first, I suppose I could see what rpm the boost starts and judge from there.

 

I went with a custom FTI