why 5 lug??

[Mach 1]

Originally posted by Robocop
?Also is it possible to have rear disc brakes and stay with 4 lug?

Yes. My friend has a T-bird rear end with disc brakes in his stang, and 4 lugs. dont know if the bird has 4 -lug axles, or if he changed them out.

and many of the conversion kits reatain the stock, 4 lug axles.

IMO, save your money. 4 lugs do the job just fine, and there are plenty of wheels to choose from.