You need to sit down and start reading, the search feature isn't so bad- it will find plenty for you to use.
Briefly, and by no means all-inclusive, what you're going to need is:
Early A V-8 throttle pedal linkage (your slant 6 linkage is a pivot rod type that won't work with a V-8)
Early A 273 motor mounts and brackets, which will need to be slightly modified to fit the 360.
Early A V-8 "drop center" steering center link.
A body kickdown linkage compatible with whatever carburetor you'll be using- 2bbl, 4 bbl.
A 22" radiator with the lower outlet on the passenger side (commonly found on '70 & up A bodies) and shroud.
Modify your wiring harness to accommodate the electronic ignition ECU and electronic voltage regulator that your 360 uses.
A 360 passenger car oil pan, pickup, dipstick and tube if your 360 doesn't already have them.
Exhaust is a cluster f*** on 360 early As- if you have manual steering, 340 ($$) and Magnum manifolds can be made to work, with some column modifications, but that will eliminate the ability to retain your column shift linkage, if you want to keep it.
Headers are pretty much Doug's and TTi, blow the cobwebs out of your wallet.
If you have power steering, you're pretty much limited to the Doug's, I believe, and the factory early A 273 manifolds. The problem with the 273 manifolds is that they're very restrictive, especially on a 360; the ports are considerably smaller. And there's a fitment issue with later 360 heads in that there's interference between the manifold downleg and the port pad on the #7 cylinder that may require a spacer (usually a bare header flange) to allow it to clear.
Either way, you will need to drill, tap, and plug the air injection holes next to the 360's exhaust ports.
Dual exhaust will require notching the transmission crossmember.
Your slant 6's 904 shift linkage should swap right over to the new trans. and work fine, as will the speedometer cable and driveshaft.
Seriously consider upgrading your 7 1/4 rear end, as well as your little 9" brakes.
Start searching and reading. This is just some basics and I know I've forgotten some stuff...
