1992 Toyota Pickup clutch problem

I recently replaced the clutch in my 1992 toyota v6 pickup that had 270,000 miles on it. After replacing the clutch I found that the transmission wouldnt go into gear when sitting still but would shift properly when going down the road but weouldn't down shift witout grinding. I took the clutch back out to make sure it was in properly and it was. I replaced everything clutch, pressure plate, trowout bearing, and pilot bearing. Also replaced the slave cylinder although it wasn't leaking and worked fine with the old clutch, but still have the same prtoblem.