The '73 440 currently in my C body still has the OEM valves and pistons in it originally installed by Chrysler.

I learned alot and made many mistakes with this engine through the 90s when I had it in my B body for many years.
MP .484 cam and 933 valve spring was the most I never used.
It did see 6200 on occasion, mostly by mistake. I was not easy on it.
These days in the c body it's stock exhaust manifolds, a dual plane, .474 cam +4, and all done at like 5300.

It doesn't really seem like there's much to worry about with the small block, it's got the same 3/8 valve stems but the valvetrain is a little lighter which should help. What are you planning for cam and springs?

If I wanted to go really mild im curious about this old manely hydro from there 73 book.

On thing I might add as well is im at 4100 ft. And the intake I will be using will be the 6bbl while my T/A sits in the barn waiting for me to die.

This also will go in a 76 duster, I can run manifolds and a bigger y pipe, or ive a extra set of tti 1 5/8 to 1 3/4 full 3 inch system or Id even consider the cheap 1 5/8 SS ebay headers and ive a set of new dougs show tubes 4 inch side pipes id like to play with as you can take the inset out and change things.

And if I need to mix fuels, that normal in my world.

But here is the manely specs. Ive some hughes single 111o springs I think I could shim and make work with this one.

My other choice is ive a mopar solid oval track cam, 509/280 106 and I really have always liked oval track cams on the street but have mostly used comps.

I like 106/108 cams rather then the wide ones.

Now the other one im considering is I ran a cam I like in some 360s ive done and fast68 suggested a hair smaller. I like the newer more modern comps because the intake closes alot sooner.

Let me check my pms for those approx specs.

268/272, .503/.510

Im good at hunting and setting up proper spring pressures but im not sure id sneak by with a single on this one.

This cars got a mild vert and 4:56 gears.

Ive some new, old manley adjustables that seem like oem mopar but just finished a hair better that cleaned up great I can use or a simple old set of 90-s comp pro mag rockers.

Im kinda just winging it as I go but will get the shortblock together this week and im waiting on a new cutter as I cant find my old one to cut the heads for the bigger valves.

Then the fun couple days cleaning up the heads. Im a little torn on hiw much to do on the heads, they are the same port like on the old MP big valve over the counter 302 heads that made good power with alot of velocity...

I wouldn’t be afraid of actual nos oe valves with a flat tappet cam one bit.

Just keep the rpm limited to below the point of valvetrain unhappiness and it should be fine.

I don't think you'll have any problems at all with stock valves.