I got it so it did better with the lll's limit switch and did some work on a duct that was S turned to make it a shorter straight run, and added an extra return air vent, but it still did "it".
Today I got the board from the friend's totalled 1998 MH, which is another lll, and the furnace ran up perfectly with no hiccups.
I was going to try the lll's plastic and so lighter weight squirrel cage instead of the metal ll's in case it was fan speed as was mentioned. I thought the lighter weight one would spin faster, don't know. It all works fine now, so I won't swap those.
Thanks again everyone for the good help!