i was wondering if the plate before the bellhousing has to b changed from the 3 speed to the nv4500 or will the nv bolt to it

 

I believe the 4500 will bolt right up

this is on yer 89 correct

 

The NV4500 uses a separate plate, which is @ 1" thicker.
The '94 up NV4500 bellhousing compensates for the depth difference.

There is also a bellhousing sold by Advanced Adaptors that hooks the NV4500 up to the pre-'94 block plate and allows the use of the 1st gen starter.

Also, if you decide to run the '94-'02 block plate, you need to use the starter for it, but the 1st gen framerail interferes with the starter.
The fix is to roll the edge of the framerail up to clear the starter.
It is a relatively small amount of interference.

Mark.