Hey guys I've decided to pull the original 383 out of my 71 Roadrunner and place it on a stand for safe keeping. I want to replace it with a 68 440. I plan to change out the torque converter regardless.. What else am I looking at changing to make the swap? Forgive me its been a few years and I forget half of what I knew about these cars. Thanks!

Exhaust manifold/header will be going up and outward. You got space there ?

Yes I should be good there. Thanks!

Are the motor mounts different between B/RB ? I can't remeber for the life of me..

I think so

the heads set 3/4" higher up at a 45 angle so anything bolted to the front of the heads (alt/power st) may need different brackets & of course the ex headers/manifolds will be raised that amt. Same mtr mts

Cool thanks very much Rapid Robert. I have all the Bracketry still on the 440 so I should be good to go.

Motor mounts are the same. Could use the 383 torque converter too.
What is the 440 out of? If a C-body then you will need to change the oil pan. Unless you have 383/400 only headers then the exhaust is fine. Not much else to change.

Almost everything will swap over ... does the car have A/C or an air grabber hood , there are 440 or 383 specific parts associated with them ? The only thing bolted to the head without A/C is the long bolt thru the alternator and the bracket that is on the 383 has 2 holes , one for a 383 and the other 4 a 440. The power steering attaches to the water pump only so that is not an issue. If the 440 is from a C body the pan will fit in the 71 K with no issues, but it won't have an internal baffle like the Stock 402 pan on your 383. If it's from a B body it will have a 402 pan if stock.

Engine mounts are the same.

If you have Air grabber the air cleaner base is different.

"If the 440 is from a C body the pan will fit in the 71 K with no issues."
Will fit but will probably rub against the center link.