Yes to accessory brackets and exhaust manifold. No to intake manifold, it won't directly fit on Vortec heads due to the mounting holes being drilled differently and a lack of the EGR plumbing your factory TBI intake uses. You'll either need the GM Performance Parts TBI intake, or a carb intake with an adapter plate. You'll also need to do some custom work around the coolant bypass to the water pump. If you check the pinned threads in this forum, there's an entire thread right at the top that tells you everything you need in detail. I've read through it several times myself because I'm working on something similar at the moment.
EDIT: Unless you meant also converting it to the Vortec intake style as well, in which case it's a lot more involved. You'll probably need the donor wiring harness, PCM, and the Vortec fuel pump as it uses much higher pressure than TBI.