'65 Barracuda, what order now ?

Read the instructions for the dougs first. Also google dougs header install for a decent read on an install on a valiant I think some good info there too. Most likely you will set the motor/trans in and leave up about 4 inches to install the dougs. I just did my 65 Dart they went in super smooth. Make sure you put some high heat silicone on the outer 4 header bolts or you'll be leaking antifreeze. I used Ultra copper on header slip joints also.
Thanks for the big response from everyone ! To qualify my actions of putting motor in by itself, I am in a small 2 car garage, I am working by myself when my daughter is at school, old hoist, etc, etc, etc. So let's start from here... The motor is sitting on mounts, the transmission has just gotten back from rebuild, bought headers AFTER I set motor in, yes I have a new Firm Feel stage 3 power steering box, car is a original v8 car so crossmember is v8 friendly, Lol ! Lost instructions but did not think to go to youtube till it was recommended. I have put quite a few sets of headers on other cars but none in a 65 Barracuda. We all know there are "tricks " to be learned for people who have " been there,done that ". The antifreeze leaks are a prime example, along with the Ultra copper suggestions. Thanks everyone and I will keep looking @ your suggestions, Tim oh yeah, I have the correct oil filter setup