If you're thinking of doing a cam as well, definitely pull the motor. You'll have to ask ordonez1307 about doing the top end swap with the motor still in, because that's what he did.

It was more work for me, but it was sooooo much easier working on the motor on a stand. Torquing the head bolts properly COULD be very difficult with the motor in, I have no idea, but seems like it might be, esp. the rear head.

in the car was a pain, especially the rear head, but if your not doing a cam, then its feasable