The cheapest way (assuming you have manual steering and no column shift) is a set of Hedman 78030 B-body headers.
Mine only needed a few dings and they're about 1/4 the price of the TTIs.
There are a few other headaches (such as the collectors not lining up with the crossmember clearance humps).
https://www.bigblockdart.com/techpages/BBody.shtml