need help for planned conversion 5.3/4L60E in 72 burb

[jmmm229]

Im sure this topic has been beat to death, but I am really close to doing this, and need all the help I can get before I dive in. I will be buying an entire truck. Looking at an 05 hard rollover. 55k miles. Plans are for engine, trans, rear end assy, fuel system, a/c compressor and p/s pump, and all electronics necessary. Possibly the rack and pinion if its feasible. has rear air so id like to keep it. is a brake system conversion feasible?
Any...and I mean any info will be greatly appreciated! I just got this bad boy torn apart, i'll post some pics soon. 72 model with original paint and not one single rust bubble! ANYWHERE! 104k miles and it spent the first part of its life as an ambulance. the 350 jumped time in 1994 and has been sitting ever since