dougs or tti headers

Quick question if y'all don't mind?
Do these headers (tti/Dougs) fit so good, can they be installed with the headers on the engine when dropping in the engine/trans?
Thanks for the info on the headers!

My plan (same way I did my Stingray) is to tie them back in the engine bay and slip the engine in between.

2 things. .....wrap them until you have to unwrap them to prevent scratches. ...and de-grease them thoroughly (even fingerprints) before first fire up.