will this header system work good with
Camaro/Firebird 98-2002 5.7L LS1 Edelbrock Shorty Header System
this performance pack and will it connect right with the exhuast
PerformancePac, 1998-99 Camaro/Firebird LS1 "Loud Mouth" Exhaust w/3.5" Slash Tips 350 HP

 

Yes that will all go together, although I and most other members would probably encourage you to save up your money for a good long tube header instead of purchasing the shorties (unless you live in CA, in which case LT's are illegal). You'll get more torque and a little more HP out of a good LT header over the shorties and the mandrel bent Y, but needless to say you're on the right track. Welcome to the forum!