who make the best header for 5.7 hemi to fit in a 72 duster

that's a loaded question.

there are the exhaust manifolds from the 09-10 Jeep manifolds actually work but tight. see this thread on for a bodies only. https://www.forabodiesonly.com/mopar/threads/73-scamp-5-7-swap.423219/

TTI is going to be the no brainier but get ready to spend a load of cash I went tti way non coated then did my own ceramic coating spray on and so far they are good, they fit awesome with Manual steering. but get ready to spend a few hours putting them in. Its a [censored] bolting them on after the motor is in the engine compartment. if you can and have the means drop the front k- member, assemble the motor and trans with headers then reinstall. if you cant do that its ok you will just be bending and using swear words you never new. its fun but takes time and patience.

there are a lot of options with TTI that's why I said loaded question. see link to TTI

https://www.ttiexhaust.com/MoparClassics-Headers/Subcategory/ccGen3.htm

I went the TTI header route after the advice of others who have done this. You do get what you pay for and they are really well made.

I was just trying to decide whether to put the engine in from the top and then headers from the bottom OR drop the K frame and put it all together and lower the car on. We have a 2 post lift too. Great timing on your post 392, I think I will be dropping the K frame now. I'm not a fan of scratching up stuff either.

What's unique about the 09-10 jeep manifolds? Curious because the 6.4 truck manifolds I have left over from my engine look real close to the pics in the thread, also hugging the block up close.

the one in your picture will exit right into your firewall, the ones for the jeep Cherokee both sides exit angled down just before the separation point of the motor and trans. they are still tricky to get the pipe in and the nuts started but very doable for sure. you may have to do some creative downpipe work.

Will headers from a modern hemi car fit an older car or truck?

Headers, I'm not sure. Manifolds seem to be hit or miss. The jeep headers seem to work on select front ends, based on the rabbit hole from the link above. I still think the manifolds I posted can be a solution for some, as they won't direct the pipe into the torsion bar.

Only one way to find out though, buy a cheap set and giver hell