yes,mag roller lifters,dog bones,spider,PRs,mag heads

yes LA headers fit the mag heads

the benefit would be higher CR and a better exhast port with more flow

any of the after market retro roller cams will work,just need to use the long nose cams for the LA t-cover and fuel pumps

if you run a mag t-cover/serp belt you need the mag t-chain and t-cover

if your 86 is already roller then mag push rods and heads is all you will need to swap them on IIRC