Doing nv5600 swap in my 97 12v and saw a guy who jacked up the front of the motor so he could get it in there easier. Is this necissary or am I able to squeeze it in without jacking tilting the motor?

 

I tilted up the front of the motor a tiny bit when I installed my last NV-4500 to make it easier.
I would do the same on the NV5600.

Is it a needed step, maybe not, but it makes it easier on me, so I do it as it is quick and easy.

 

Do I need to undo motor mounts or anything or can i just use a block of wood and floor jack on the front?

 

I loosened my motor mounts and removed my down pipe when I did my clutch and NV-4500 job last time.

I was upgrading the down pipe anyway, but it sure helps with getting the engine to tilt easily, if it is not mounted.