When I removed my 5.4 I had to let the air out of my 4x4 but I have the torsion bars cranked with 305's, so, I had no choice. If you can do it without letting the air out then go for it. As far as the exhuast manifold bolts bending I do agree with the above post in that if they are not flush to metal they will bend, hence why I fabbed the brakets that I did. I could crank my header bolts all the way down to the 1/4 in. metal brackets and then I just hooked the chain to my brackets. Once there, I unbolted the mounts from the block and raised the engine about 1 inch, slid the cherry picker back just a fuzz, and raised that monster out of there. The next thing to remember is to have an adequate engine stand because unless the one you used on your old GM motor is rated for more weight it may not work. I believe that these motors weigh in around the 500 lb range, maybe more, but the stand I had was rated for 700 lbs. and it was bowed over pretty good. Best of luck.