3" lift question

[BurnoutNova]

im going to buy some springs and bocks from a user on the board, 2.5" springs and 3" blocks, and shocks and whatnot

my question is wont i need bigger blocks than 3" for my 69 k-20? it has blocks already (1"??) they apear factory, and it sits level. i was thinking i'll need like 4" blocks?

i know this is a stupid question but ive never done a lift and dont want to (but always do anyway) run in to any probleoms



thanks, zach