From what I am told , you should forget those headers... I believe MTS has some bolt in headers for your car... if not the best thing to do is get a set of BBC headers and weld on caddy flangers...as for the the early intake, it will work great... the rear compressor mount may be different.. if so, you will need one from the early intake.. If you got the motor out it is best to change the timing chain and gears... get rid of that plastic gear and put in a good roller chain set-up... no cheap ones, good ones are about $100
I tried the BB Chevy header route. Not worth the hassle in these cars! You really need to have custom headers made, since the BB Chevy have too many interferences with the '79s frame.
The block hugger headers I used only needed some slight mods to the drivers side to fit right.