Just my 2 cts.worth.If your going with a new crate motor and a 700R4 tranny,why not just put in an aftermarket M2 frontend.Mine is a TCI,and there are a lot of other good ones on the market,Heidts,Fatman,etc.Good luck with whatever you decide on.As far as lowering the rear TCI has a nice kit available,which includes new 5 leaf springs,mounts,shackles,shocks,spring perches for flipping the rearend,etc.