Body Filler

[Mr79C10]

Whats the main differ. between light weight and reg. weight and when to use what where?
Im getting ready to start the body work on the '79 C-10 short box and I dont want to buy crap I may not need.
Also, any help on the products such as sanding, what grit to start with and what grit to ends up with to get started on primming.
which leads into the questions,, Whats every ones pref. on products such as body filler and primmers?


Will be sharing pic's as project goes along. Just completed with a 3/4 drop kit, ( control arms, hangers and shackles)