Silversport Transmissions has a complete kit but you'll pay around $5000 for it. It's everything from the back of the motor to the rear axle. I built my own.
Crossmember - I built my own.
Speedo - If you want to use your mechanical speedo, there is an adapter you can use or you can switch to an electronic speedo.
kickdown - modern transmission do not use kickdowns. It is all computer controlled.
Trans lines - you would have to make your own. For now I just have rubber lines on mine.
Shifter - If you have a slapstick you can get a kit to convert it to the chevy trans and just us a shifter cable instead of the links.
Driveshaft- have one made.
Controller - Im using a microsquirt trans controller. It's fully programmable via a laptop (shift points, line pressure, lockup, etc.
Quicktime bellhousing - big block mopar to 4l60e
Flexplate - This was the biggest issue I had with the whole conversion. I had to modify a quicktime flexplate to get it to bolt up. I also had to use a spacer. I think I ordered the wrong flexplate but I was able to make it work.
Torque convertor and trans - If you get the quicktime bellhousing, you have to use a 4L65E trans. the bellhousing is listed as a 4L60e bellhousing but It will not work. Trust me. I found out the hard way. When Chevy switched from the vortec to the LS motors, they changed the torque convertor and input shaft along with some other beefier internals in the trans. I had to get my input shaft and torque convertor switch over to make it work.
All in all, I have roughly between $2000 - $2500 in the conversion. It was definitely harder researching and sourcing all of the parts I need but in the long run, I think it was worth it. If you want a bolt kit and not have to search for this and that, I would just buy Silversports kit. I think they have a list of all the parts on their website.
https://shiftsst.com/articles/cat/mopar/post/charger-gtx-super-bee-1971-1974-perfectfit-kit/