I apologize if I came across as not offering any help. My concern was the set you were looking at were being sold as something that originally came with the car from the factory. Or perhaps they were specifying their hookers were an earlier model run.
The reason you are being asked a lot of questions, and not just being offered specific products or opinions is because for the 351C a handful of different types of heads available from the factory and a few that are aftermarket. Above performance considerations, which is what I was alluding to in my original response, there are two original factory port sizes. We refer to them at 2V and 4V. Headers and exhaust manifolds are technically interchangeable (you can bolt them on) but they will leak if mismatched and performance will suffer. Additionally you mentioned you have Trick Flow aluminum heads. I just did a cursory look and there are 8 different models available. I didn't dig into which port sizes they used or if they have a custom size. Using the stock heads some header models get very close to the power steering, if your trickflow heads have altered the location of the exhaust ports this might cause an issue.I think there
I run hookers. I had good luck with their 2v comp headers. When I went to 4V heads I had good luck with their supercomp headers except they hang pretty low and after mashing one (my fault) I replaced them with a set of new ceramic hooker comp headers.