Harsh 1-2 shift

[Chevy366]

A lot of people get this problem with the TransGo kits, kit is designed to enhance the stock tables without adjusting tun values, if you add kit to a tun that is already adjusted to make stock plate shift firmer it will be to firm. TransGo needs to be more specific in the shift firmness details, firm means real hard shifts in TransGo terms. Try stock table values then adjust from there.
You can shot peen the holes to make them smaller.

[johnmaster]

I tried stock values for a 2500 and then mostly zeroes for up to about 150 ft lbs torque and was still bangin gears...reduced mph helped but I still feel a little clunk I would someday like to get rid of. I think thats the way I left it, need to spend some time revisiting my trans tuning, need to work on the tc tuning as well, I have it disabled for simplicity right now.

I hate to make the hole smaller as my 1>2 under heavy throttle (full pressure) feels pretty good or a bit light if anything.