Why not replace the engine with a full oil pressure Hudson 262 or even a 308?. This would be the very easiest and the cheapest. Almost every part will swap over, with only having to change the exhaust header pipe and a couple of different accelerator linkage pieces?.

I’m not opposed to that at all. Honestly just figured it would be cheaper to swap a 300 and much easier to find one and find parts for one in the future.

I like the Ford 300-6. It's very reliable, more modern OHV design, more fuel efficient, and more power. You can get parts locally almost anywhere. It was used up through the early 2000's.

But as Doug suggested, getting everything to adapt will be the hard part. Thus his suggestion to stay with a Hudson 6.

What transmission do you want to use?  Manual or automatic?  That will be important in deciding on the rear end ratio. Let's say that the final ratio through whatever transmission you select is roughly 1:1, then you probably want to stay around 3:1 at the rear end. If you want more highway cruising gear, then drop that to around 2.8 or even lower.

Transmission I’m not really sure on. I’ve gone back and forth. It’s got a three speed manual now but I thought for ease of kids/wife driving it in the future an auto may be the way to go.

The car is basically a shell. It’s in decent shape body wise but all the engine and electrical components are completely shot, so I am basically starting clear over.

Ben, that is the problem, getting all the parts to make a swap. Things you will have to re-design??, first, getting the engine to sit in the engine bay. That isn't that difficult. About the only thing the same is the exhaust is on the same side. You will have to make custom accelerator linkage, now depending on the transmission you use, if an auto, the rear axle ratio will not be correct, and will require a different rear end. Next, if you do choose a stick shift, it will now be floor mounted, not column, so that will all need to be re-engineered, and the list goes on and on. On this scenario, you will need an engine, trans. and probably a new rear axle, that provides the correct ratio for an auto trans. and if you keep the Hudson rear axle, is it good enough and not all worn out, like most.
Now, if you look at using the Hudson 262/308 engine. You need an engine, but almost everything else is straight forward your looking at it, but it just needs restored! Those few simple words here "it just needs restored" is usually way MORE than most persons understand when taking on a complete restoration. Having to basically re-invent the wheel so to speak, will cost lots of time and $$$$. If you are not familiar with the Hudson 262 C.I. engine, most would agree, it was probably the most dependable, and lacks no problems with power.

A Hudson wide block 51+ 262 would make a nice swap. Agree with Doug, way less effort than a non hudson motor. Should be very available as well. These have insert bearings with pressure oiling and less costly to rebuild than the 8 cyl hudson.

In a Commodore, i would not even consider a manual, and certainly not a floor shifter. I can only foresee difficulties getting clearance with the bench front seat. It ain’t a performance car. It’s a 4-door sedan. use an automatic, especially if anyone else will drive it.

My 1953 Hornet, which is the same stepdown chassis and body as your Commodore, has the 308 and Hydramatic auto. The 308 pushes it around pretty well, but nothing like a more modern V8 would. It also gets crappy fuel efficiency—about 13MPG highway if i keep it under 70 MPH. Less in town.

If i were contemplating an engine swap, for the effort involved, I would do a small block Chevy or Ford V8 with a GM/Ford automatic. Some one else here is/was doing that conversion and you should search for that thread.

Doug,
You make a lot of good points. I was under the impression it wouldn’t be quite so difficult. Sounds like my best bet is to find a Hudson engine. I put a feeler out on Facebook and will check the classifieds. Do you have any other suggestions on where to look? Closer to southern Iowa the better. I know you’re a busy guy, appreciate all the input!!