I don't see how they could have driven these things back in the day, or I've got something wrong. 73 Cuda with a 340. Under moderate braking you can watch the oil pressure drop from 40 to 20 psi. With semi-hard braking it goes to nearly zero and the red light comes on until it recovers. I don't remember this happening with my '72 318 Barracuda way back when. Is this expected? I really have to pay attention so I don't give it the beans right after slowing down. I don't want to wipe a bearing. Stock 294 pan, it's a little beat up on the bottom but I don't' think that should affect this.

Ever check oil level ??

I had a 318 Volare that would do that. I thought it was kinda handy---you can check your oil level on the fly with a simple brake dump!!! lol!

Run an extra 1/2-1 quart if you have too. A better option is to use a baffled oil pan (I bet yours isn't).

at the RPM issue when you start braking, if you let off the gas without braking does it drop the same? I'm thinking oil level/pickup clearance. the first thing I would do is toss in another qt (maybe 2) & see what happens. that extra ain't gonna hurt for a day if the level is OK right now. I'm thinking the dent in the pan or partly clogged pickup if there is enough oil present.

Pickup screen probably too far from bottom of oil pan me thinks.

Probably so
OP, you can check the oil pan pick up height from the bottom of the oil pan by removing the oil pan drain plug and stick a small thin bladed screw driver in that hole and move the tip up and down to measure to get a idea if it is touching the bottom of the pan or way above the bottom.
I use the dip stick when I'm building motors on a engine stand, if it won't slide under all the way I'm good, if it does and moves up and down a bunch I'm going to adjust it so it touches or the dip stick will only slide under it sideways or maybe the width at the front and call that good, any more is NOT GOOD
As already mentioned all the stock SB oil pans Mopar used don't have acceleration or deacceleration baffles in them
You have to add them

Just FYI, my experience with it was on a 318 with a known history from new--it was my moms car, oil pan never off, and never dented, meaning whatever the oil pickup distance was, it was that way from factory.

As I recall, if the oil was around 1 quart low, heavy braking would do it.

294 pan have any baffles at all ?

"A little beat up on the bottom"?
That's likely the problem.
I can't recall ever having that problem on a stock/street Mopar unless I put the thing on its nose with HARD braking, and the light would flash momentarily. But that's a dim memory from many years ago.
I once had a '71 TransAm that would starve itself of oil during hard cornering. Pretty ironic.

No idea if the pan has baffles but I'm thinking not. I changed the oil and filter a couple months ago and it checked fine for level and it doesn't leak and I haven't driven it until today. Regular deceleration by lifting off the gas has no effect. I'll check it again and will put a little more oil in and see how that affects it. Won't be driving much before it goes to storage for the winter.

A new baffled pan is on the wish list but the current headers won't allow one of the wide ones so I may go with the Kevco. If the budget isn't there I can always add some simple baffles to the current pan. There are a couple DIY's out there and I have a MIG so I can be considered dangerous.

I'm thinking the pickup is high in the pan and considering the BS I've uncovered up to this point on the car, I wouldn't be surpised if it was hacked up.
Maybe that is why the previous owner had almost eight quarts in it when I dumped it after bringing it home....?

It does not have any.

My fury would act like that with the stock pan. A little more body to flop up and down though. I baffled my pan and it stopped.

I think everyone is on the money with pickup height being too high. I can't think of anything else internal to the engine that cares much about fore/aft movement with speed changes. And yes running eight quarts would probably get the level up above it, LOL.

When my 360 was leaking like a seive (but the pickup set right) it wouldn't start the oil light blinking during braking trick until about 2 quarts low.

As for the pan being beat up... Many years ago they started the repaving process on a road in my town. Starting with putting manhole risers on which stick up above the road to account for the planned thickness of the new layer of pavement. Guess what, someone forgot to close the road. So I drive down it, see it coming but not in time to stop or dodge it. Put a huge dent in my K frame, then hit the oil pan and put a good inch or so depression in the pan. How it didn't catch the bottom of the transmission I have no idea. Anyway with that big of a dent it never caused oil starvation issues like you describe.

Checking and resetting the height is probably all you need to do for normal driving, although the stock capacity kevko pans are pretty trick. I wouldn't worry about an extra capacity pan unless you have a high volume oil pump and are spinning it way past the redline of a stock engine.

I checked after work and it was 1/4 qt down at the most. I put another quart in and will see if that affects it much. I'm sure it will be better but the positive solution is a baffled pan, which will happen at some point.

R u able to dig up TWO spare 294 pans ? PERFECT way of checking pickup location in the pan and way to position the baffles