The th400 in my lark has always shifted early. I have played with the vacuum modulator and it helps a bit, but only by about 200 rpm either way. I've got a 2500 stall and the motor makes 12 in. of vacuum. One question of my is will the modulator stop when it is turned all the way in, or will the screw continue to turn? Any ideas? Jon
I think the screw will bottom out and stop at the limit of adjustment...but don't quote me on this. Might not hurt to pop out the governor & see if everything's moving smoothly & hasn't worn anything too much. Devon
