Will not shift out of 1st

Going over the list that 72plymouth posted...
-fluid level... good
-throttle linkage adjustment... I assume the kickdown, tried in mulitply spots
-line pressure too high or low... I assume this is controlled by the kickdown and again I've tried multilple adjustments
-oil pump malfuction... it seems to be pumping fluid (there's fluid at the cooler
-shift lever adjustment... it's good

So, what should I look for now? Stuck governor? Can I check this w/ the trans in the car?