I have just begun the project of ripping out a perfectly good 360 and putting in a gen 3 with a manual 6 speed in my newly acquired 72 Demon. Here is a summary thus far. I am going to utilize a Cleveland Power pallet 6.1 Hemi from a 2010 SRT Challenger equipped with manual tranny, A HDK front suspension and again Hemi Denny rocks he is my new hero. I will utilize the fuel tank from the modern Challenger as well. It will be equipped with power steering and potentially A/C. I will do my best to outline the issues as they occur so someone else can learn from my mistakes. While I am an excellent fabricator I would not consider myself a mechanic, more of a parts changer really. I am mediocre at best on auto electrical. I have spent my life fabricating and welding/ millwrighting in food plants tied to Ag. I am handy with plant PLCs and three phase but a car heater scares the crap out of me! What I am trying to say is that if I can try this I think most anybody can. There is a wealth of knowledge out here on this website, you have but to ask and someone has done it already and got the shirt. This is my long winded intro, normally I will be far more brief. I will keep ya posted as I go and once I figure out how to post pictures on here I will do that as well. Anyone wants more details give me a holler on PM. Or anyone has any advice feel free to ping me. Woo Hoo here we go!