Engine dyno vs chassis dyno

I like both...Engine dyno after a freshly rebuilt engine/stroker motor, to figure out all the quirks, leaks, best tune, and cam break in...

Then chassis dyno once it's in the car...I had my stroker motor broken in on an engine dyno and was glad I did because a couple roller lifters failed...quick call to hughes engines and a new set was mailed to me...

Once I have the engine in the car, I'll have it chassis dyno'd..I'd like to know the actual RWHP. It will be interesting to see how much power a 4 spd, and Dana 60 with detroit locker takes up...