Rebuild bottom end needed?

[mug23]

So, I purchased a used motor. Asked the seller if it spins over and he said yes. I didn't have the tools to spin the motor at that time so I took his words for it. Once I got it home, I try spinning it and it wouldn't rotate. I knows that it is hitting the valves. Took the rear cover off and 2 guides were all shattered all over the place. The crank to the cam timing is so far off due to all the guides are gone from being all shattered.

Anyways, I struggled to pull the cams due to the cam cap bolts very tight but at the end, I would able to pull the cams. Once the cams were pulled, the bottom end spins freely with no problem. However, I decided to pull the heads off and see how much damaged on the pistons. Below I took picture of cylinder 1-2-3-4 bank and the piston does show hitting the valves. One cylinders 3 and 4, the middle intake valve is not seating back to the normal. The rest of the valves are seating correctly. Do you think those 2 valves are bent?

What do you think? New piston is needed and a engine rebuild? Can I just maybe have a machine shop to only replace the 2 potential bent valves? Can I just continue using these pistons?

[Monty23]

The pistons will be fine as is. I would clean the carbon off and "lightly" sand any sharp edges from the valve contact into the pistons. Any valves that touched pistons are now bent. If you want to check to see if any valves are leaking on the bench in the heads, fill the intake and exhaust ports with a decent amount of break clean and watch the combustion chamber side for any fluid that leaks through. It should be very obvious which ones are leaking. But the machine shop should remove and check the valves for straightness with a go/no go gauge.

A cheaper option might be to find a good used set of heads and slap them on.

[mug23]

The pistons will be fine as is. I would clean the carbon off and "lightly" sand any sharp edges from the valve contact into the pistons. Any valves that touched pistons are now bent. If you want to check to see if any valves are leaking on the bench in the heads, fill the intake and exhaust ports with a decent amount of break clean and watch the combustion chamber side for any fluid that leaks through. It should be very obvious which ones are leaking. But the machine shop should remove and check the valves for straightness with a go/no go gauge.

A cheaper option might be to find a good used set of heads and slap them on.

Thank you for the reply. I'm pretty sure few valve is bent as couple of them will not seat without the cams. I will get the heads rebuild. My next questions is, I'm worried about the cylinder bore. What's the best way to check the bore for score?

[BallnchainB6]

Turn the crank to lower the pistons and look for scoring. If you can feel a scratch with your finger nail, it requires attention.