I am under the impression that there is a kit that will convert 3rd gen F-body brakes onto a 1st gen chevelle??? anyone have input on this??

Third Generation F-body (Camaro, Firebird and clones) was from '82-'92

Fourth Generation F-body (Camaro, Firebird and clones) was from '93-'02

Your title was for a '99. Nothing is interchangable from a '99 F-body, but some guys are using the '98-'02 "LS1" (really a C5 PBR caliper with a different abutment) with the stock '64-'72 GM A-body drum brake hub to see if the 12" or 13" C4, C5 rotors will work with a custom bracket for brakes on their car. And a lot of guys are running the rear discs from '93-'97 while others are trying the swap from the '98+ models.

Your text question was for a third gen. F-body. The RPO code 1LE on third gen. f-bodies included 12" discs up front and C4 sourced PBR calipers on all four corners as well. The 1LE front 12" rotors will swap onto "tall spindles" that are a popular swap for our GM A-bodies. They have the correct 5 on 4.75" bolt pattern but use metric wheel studs (not really a problem). Some third gen. F-body rear discs are also worth swapping onto our GM A-body rears as well, though you'll need a Chevy 10 or 12 bolt for a direct swap.

Good luck,
Joe

yea, my bad I meant 4th gen. Thanks for the info