When you were getting on plane, was it coming up easy or did you work at it or let off for any reason?

Valve guides were too tight. Both exhaust valves stuck open and the pistons hit them.
Have the heads rebuilt again the right way and replace any valves that have scuffed stems as well as the two that are bent.
The fact that the exhaust valves stuck tells me that they were too tight. Those stems get hot.
Did anyone do a plug check to see if it is running lean on those cylinders.

Yes checked plugs no sign of running lean

Any chance piston to valve clearance is too tight. A lot of aftermarket piston makers raise piston deck to reduce the 016 to 020 in the hole pistons leave the factory at. But whatever it is, count your blessings. The valve heads are still attached to the stems, instead of stuck through the cyl walls.

can we see the plugs,,we may see something different.

Sorry about your bad luck but in some ways it looks like you got off easy - having parts touch with no catastrophic results is good luck in some ways (if that offers any solace)

Clearance on the exhaust side usually isnt an issue, i agree looks like he stuck a couple valves, any idea what the clearance was on them? Maybe they didnt put assmbly lube and they were dry when you brought it up to 5k?

If the 5&7 wires are touching it can cause detonation, but not this extreme.

Clearance was my thought as well. May be so close that they just barely teenage kiss or peck on the cheek. Clearance or guides too tight. I'd think anything else would've caused much more damage. What's the exhaust lift? What spring pressures?

If it had been V/P clearance it would have shown on more than just those two. And it takes a LOT more than a kiss to bend a valve like that. Those valves were open when the piston came up.
Made a V/P clearance mistake YEARS ago and had the valves just touching the pistons. Every piston showed slight contact. At 7000 RPM one of them let loose. SBF 302.
12.5:1 compression and solid roller cam. engine made over 500 HP NA. Engine had 5 hours of unbelievable performance before it let loose.
When that engine was idling it would make your voice sound like you were driving down a bad washboard road.
That was the engine I had in my Glastron CVX 18 that did 95 MPH.
Everybody that saw me drive it thought that I was nuts.
It was a white knuckle drive. At 95 that boat was past the edge.