Sounds like you have possible low fwd drum pressure or you have no friction material left on the drive plates. I would compare fwd and rev pressure and main pressure. Does the unit shutter before engaging harsh?

Does the temp of the trans play any role at all with this delayed engagement?

the fluid is a lil dark but not too bad linkage is all good we do have a little bit of slop where it goes down into the top of tranny but it is shifting into drive becuase it pulls engine down just wont pull until you rev and i guess it fully engages

First i would check the fluid and make sure it is full and not burned. If it is very dark and/or smells burned change it and the filter. Also while drained pull the sump filter located at the base where the main return hose mounts and clean it out.
check the inching cable adjustment too and make sure there is no tension pulling the inching rod linkage or make sure it is fully releasing when pedal is released.