There was one report of TA headers having so little ground clearance they were nearly unusable.
I have a set of Kustom headers on my blue '66. I think the GSCA and TA repos are copies of those.
To install, you have to unbolt the engine mounts and raise the engine. Drivers side is more difficult, you have to unbolt the starter to make room to fit the header up there. The original starter is more easily installed if you remove the solenoid until you get the starter body in place, then put the solenoid on afterwards.
To get the oil filter in & out, I have to remove the trans converter cover and loosen the trans cooler lines....That's with my Kustom headers. Do you guys with the TA's need to do this too?