Troy,
I really appreciate your offer of advice. IMO '69 Firebirds are one of the greatest styling jobs ever done by GM. Certainly on my wish list.
I didn't get into depth with the other fellow I mentioned above.
Here's the link to their LT-5 into a '67 Camaro project.
http://www.lateral-g.net/members/mitchell/
Since I haven't a purchased motor and trans yet, based on what you're going through, does it make more sense to use a different manual tranny?