Headers vs. Manifolds

I weighed everyone's advice and thought about the power I'd lose and decided to buy some B-Body headers and do the minimum necessary clearancing.

This might be a case of using the wrong part name, but I thought this was worth mentioning to make sure you get the right parts. Your info above says you plan to get B-body headers. The tips in all the responses talk about the viability of B-body manifolds.