Just a few quick comments on the swap.
Mounting the 500 on a G Body front clip should be close to what I had to do to put a 500 on the El Camino. I offset my engine to the passenger side a bit for clearance and depending on how the things line up on your 52 you may or may not have to do this. My build thread pretty much covers what I did for mounts and locating the engine.
https://gbodyforum.com/threads/500-cadillac-in-a-g-body.25458/
Not knowing how the engine is currently set up with the original frame, a couple of things to look out for.
If you don’t already have one on the engine you will need a rear sump El Dorado oil pan to clear the front crossmember. You might also look at the drain back mod I made to mine to alleviate having to drain the front sump.
To run a factory sway bar (strongly recommended) you will need to use the 425 Cadillac off set oil pump for clearance.
While bigger is always better, I’ve been running the stock front brakes on my El Camino for the last 8 years/85,000 miles and they are adequate and I have no inclination to change them.
Front springs will likely need to be upgraded, but that will have to be done based on what the front end weight is when you get everything pretty much finished up and your preference for “feel”.
Good luck with the swap.