new guy from Australia

[Plodge]

hi all,
came across this forum while looking for info on parts for my truck.
I have a 72 GMC lwb,just a basic 350/350 tidy truck. I have just bought a Vintage Air kit and am looking to lower it too. I already bought 3" drop spindles and am considering a rear flip kit from DJM.
Anybody done this before?
do I need to notch the chassis?

for those wondering about my username, I used to have a 33 plymouth street rod that was part dodge and part plymouth, so it got nicknamed Plodge. I have sold the car but the name has stuck with me

I own an autoparts shop here in Perth,as well as the truck I am building a 32 ford hot rod and I have an aussie GM car as a mild custom for weekends.