okay, if you are using stock exhaust manifolds, you will probably have interference issues with steering rack, also, I believe the starter is on pass side of 5.7....you would move with 727. Look at radiator outlets, based on motor truck vs. car. I think oil filter might hit stock k-member? there is a great post in archieves about install into e-body. lots of pics.....
My opinion, go with new hemi, I am wrapping up 6.1 in 71 runner, and it is a winner. (also about 200 lbs off of the front of car!)