Only other way without changing the govenor springs would be to adjust shift points down,or adjust with the high idle screw\govenor spring adjusting nuts.
If you raise the high idle your shifts points will go up accordingly due to the TV cable travel. You will have to readjust the cable afterwards.
You can crank the govenor spring adjustment nuts down one or two clicks,but idle speed will go up accordingly. This is supposed to give you a couple hundred RPM more,but I could never get it to work without problems (slow return to idle,stuttering off idle,etc),so i went back to stock settings. Give it a try,it's free,just keep track of what you do so you can go back if it doesn't work out.