(Newbe) 273 to a 340 and tremec 5speed swap.

The 340 swap makes WAY more sense than the 440 swap! The easiest route with this swap, would be to buy what the dude has, sell the Tremec and related junk that goes with it and swap an A body 833 4 speed setup into the car. You could buy every bit of the 833 swap stuff off this forum, or just pony up and buy it from Brewers for known good stuff. @Dan Brewer has anything and everything you need to do an 833 swap. That's his family business and he's been at it along with his dad Wayne, since he was a kid.

Do the headers in the pic come with the motor? If so, find out what body they fit and what brand they are. TTI or Doug's headers are A body specific and there is a difference between Early A (64-66) and Late A (67-76). If you swap to a 4 speed, you also need to be planning to swap the rearend to an 8 3/4. The rearend in the car will grenade pretty quickly with a hot 340, 4 speed and a young man that enjoys the new found power with gears to row. Don't ask me how I know.....lol. Good luck to you George. It's nice to see your enthusiasm and I admire your patience and respect with the comments from some of the grumps who've forgotten what it was like to be new to the car hobby with little to no experience. You'll gain experience with every bolt you turn! Hang in there man. :)