727 hanging in 2nd gear

I recently put new clutches and shift kit in my 727. It now has quick firm shifts. The problem is I have to drive about 5 miles or so before it will shift into 3rd. Once it shifts to 3rd most of the time it will be ok and shift normally til turn off the engine. Then I have to start the whole process over again, even if its only off for a minute. It also has no kickdown when you floor it and I have adjusted the throttle valve linkage. Someone told me it could be the governor. Thanks in advance for any help.