I'm in the process of installing hedman shorty headers right now, and despite the claim they are an easy fit, wil "slide right in" etc, bs, bs,, bs.
Dont believe it.
Some people say the $$ ttis are the best fit for a big block, but EVERYONE will tell you, and there are hundreds of guys on this site with experience with headers in general, they are all a royal PITA. Fitment issues, and having to bend them and crimp them or heat and bang on them are just about a universal necessity.
I just paid $400 for ceramic shortys which DO NOT COME CLOSE to fitting. I have practically destroyed them to get them in and I am PI$$ED.
At least I still have my 1-7/8" long tube hooker comps.
Maybe I'll get them coated, and bent professionally here and there, and put them back on.
I only replaced them because they were rattling against the torsion bars and the steering box, and I apparently still have that problem.
Search this site for header information like I did and you will find hours of good reading material based on real world experience.
Also check the mopar magazine link in one of the threads for the hedman header article and dyno test results. Lots of good stuff in here.
Good luck.