Projects 52 Plymouth Cranbrook Restoration - Need advice

Hello all!
I have a 1952 Plymouth Cranbrook project I am working on, and need all the advice/tips I can get.
I bought this almost 3 years ago as a "beginner resto project", and I ended up encountering so many issues that I got discouraged and started to think it was an ill-fated attempt.

Long story short, I just found a flathead 6 in the area that the PO says was rebuilt somewhere around ~2-5k miles ago. I was able to get the engine on the frame, and fire it right up!
So now, I am looking for advice on what to check/verify before putting the engine back in? Currently, the body is off the frame, and I am just working with the engine. My thought is that if I'm gonna do any maintenance or repairs that I need to do it now before putting it back together. So what should I check? I need some guidance as I am honestly just a beginner who doesn't know too much. I would really appreciate some tips from you seasoned veterans.

Currently, the only issue I'm aware of is that it has a bit of an occasional sputter. I am unsure of what this might be from, but here is a link to a video of it running if you guys want to listen.
Also, I have a bunch of new engine parts(as I thought I was gonna be rebuilding the last engine), so if you have any suggestions on things to replace, I may already have the parts!

Thanks in advance!!

Here is a video of it running.

 

That engine sounds really good. I’m sure there will be many ideas here. Could the noise you’re hearing just be an exhaust leak. No gas leaks from dried out gaskets in the carb?
Check out the P15-D24 forum. These guys live flat sixes.

 

Thanks for the heads up! I'll post over there!
Do you mean an exhaust leak from the manifold, or from a sticky valve?
If you mean from the manifold I don't think so, but as for a sticky valve or something, I have no idea...

 

I was thinking exhaust but I really couldn’t here anything alarming from your video. If it’s holding good oil pressure and not getting hot, I’d just run it a bit to loosen it up. Did you put new oil and a filter on it?

 

I hear a god awful clanking , like something loose in the valve train