ok, one thing that is driving me crazy on my 03 silverado is under light throttle low speed driving the 1-2 shift seems to come out of 1st and "drop" into 2nd with a clunk. The truck just turned 58K miles today, and im not sure if the fluid has ever been changed, but a full fluid flush is on my short list of maintaince stuff to do.

I want to find out if its better to tune the PCM for better shifts, or install a transgo HD2 kit. I have a brand new kit here already that i bought for my previous car that got totaled, and never got to install it. Im not looking to bark the tires on every gear change, but i do want firmer than stock under light throttle, and maybe alittle chirp on the 1-2 shift at WOT, but nothing that will be neck snapping as the wife will just say i ruined it by messing with it.

I do have some bolt on mods planned for the future, but probably wont go beyond that with the stock 5.3.