So long story short my choke was getting stuck on the drop base air cleaner and has resulted in my 440 being pretty carboned up. I checked the top of the pistons with a scope so I can confirm its the issue. I've tried seafoam as well as the water spray and its helped a bit but I still get detonation due to the carbon on the pistons.

Does anyone have any other tricks or am I stuck with pulling the heads and doing it the hard way?

What I did that worked years ago is to connect rubber tubing from the washer reservoiur motor to the carburetor opening and attach above the throttle plates. Fill the reservoiur with water and run the car on the highway.
Every few seconds hit the windshield washer button to spray water down the carb. This works because you are decarbonizing the piston tops when the engine is under load full temperature..

Sounds feasible: guessing you'd want some sort of smaller small hose/spray type nozzle at the carb end. Don't want to inject a "gulp" of water each shot.

Old trick we used in the 1960's and 70's. Start up the engine and let it warm up a little, slowly pour about a cup of transmission fluid down the carb. You will see smoke come out the back, shut engine off quickly and let set for about 20-30 minutes. Restart engine and rev it up a little, hitting the pedal a few times until the exhaust clears up. It has cleared a lot of carboned up engines back in the day when lead was in the fuel plugging the cylinder heads. I've seen chunks of carbon blow out, back in the day.

i remember when we were still a GM dealer.
someone brought in a C3 corvette that was owned by a older person who only putted around town with only short trips so it never really warmed up. the new owner tried driving it like he stole it but had a pinging problem like you describe. the driveability tech used some GM top end cleaner. he got the car HOT. then removed the vacuum line for the brake booster and stuck it in the can. he reved it up and it sent out a big black cloud out the exhaust. after he emptied one can he took the second can and did the same but not rev it up so much. the car quickly died. after it died he poured the rest down the intake, he killed the coils and cranked it over while pouring. and let it sit overnight. the next day he fired it up again, it smoked like crazy. he ran it until the additive cleared out. he changed the oil and the problem was gone.

I actually used the same windshield washer resorvoir hose from the washer pump to the carburetor. No spray nozzle was used. It worked well.
If you want to put a spray nozzle at the end of the hose; maybe go to Lowes or Home Depot and buy a misting nozzle that's used for outdoor sprinkler systems to water shrubs.
The misting nozzle line attachment is about the same diameter as the washer hose.

Did the same only used a whole quart (Not synthetic) and ran it at 2500 rpm (never turned off) till it stopped smoking.

Mopar’s official brown foaming spray has worked very well for me, including on heavily carbon’ed up EGR passageways.
It makes a huge cloud of black smoke.

https://www.morris4x4center.com/mopar-combustion-chamber-cleaner-13-oz-aerosol-can-4318001ad.html

As an experiment many years ago I used a second pcv valve to suck ac conditioner drain water into the intake manifold of a 1995 Magnum 5.9 V8 for over two Summer months. This made an odd noise in the passenger compartment of the pickup, slightly lowered city MPG, but did clean carbon off the tops of pistons.

Well I have some old partial cans of trans fluid that might be the next experiment. We will see how happy it makes my neighbors!

Does your vehicle have a cat? If so better take it off.

It has detergents in it to keep valve bodies clean. Also was a 1/2qt substitute during an oil change for sludge.

Its a 1967 440 no emissions issues here

Try mixing some white vinegar with the water being injected, it works on coffee pots.

CONSIDER a mild water injection system ... clears EVERYTHING up

I remember my dad taking the garden hose out to his 71 Cutlass, he started the engine up, let it warm up, then he rev'd the motor up, probably 4000rpm and turned the hose on... I was like WHAT are you doing. he said cleaning out the carbon, today's gas is junk. Well you should have seen the mess coming out the tailpipes. Car ran like a top.

I was taught back in the early 1960 when all gasoline had lead in it to use a spray bottle full of water only and warm the motor up to operating temps and then spray enough water down the carb slowly at or above 3000 RPM to start to slow the RPM down a little, 200 to 400 RPM, for as long as the water bottle had water in it, probably around 8 ounces That worked really good on cleaning out the carbon

Be careful when running any type of oil thru your engine while parked in your yard. A few years ago I had a turbocharger come apart. After replacing the turbo I fired it up and the smoke cloud was so thick someone called the fire department. I had cops and firemen coming thru my driveway gate because they thought my shop was on fire. I had to wait till 1:30 one morning to fire it up and drive several miles up the freeway to clear it out. Neighbors don't take kindly to their backyard picnics getting smoked out.

A very GENTLE application of water into the combustion stream is very effective!

Remember Edelbrock's water injection system? It was for detonation suppression, not decarbonizing, but water is water. I recall a car mag article about building your own using a vacuum switch to turn on a windshield washer pump under high engine loads.

I saw an old guy who was a drunk do that He used a Beer. He says One for me and One for the car. It did work but only cleaned one of them up