I would definitely use the valley pan gasket again, get a new one. The valley pan gasket helps keep the intake cooler by keeping the hot oil away from the bottom of it. If you had a bent pushrod that was out of place, then you were running on 7 cylinders, which will definitely kill power. You can just replace that one pushrod, you do not need to replace all of them, but if one pushrod is bent, I would check them all. Please be aware that when you remove pushrods, they must be reinstalled exactly where they were, in the exact orientation that they were in. Pushrods, like lifters, and rocker arms, create a unique wear pattern between one another, they must be installed exactly where they were or you can create wear issues and parts failures if you move them around. Take your pushrods out one by one and check them on a plate of glass, just roll them over the glass, if they are even slightly bent you will see them wobble when you roll them over the glass. Replace any pushrod that is even slightly bent.
I can't see anything else that looks out of place on the photos, the one strange thing is that the last rocker arm on the passenger side of the engine, seems suspiciously clean, and so does the pushrod, may just be the photo. Maybe someone had an issue there before you and changed that rocker and pushrod? That engine has a little too much dried and gunked up oil and dirt in it, which is normal if this is an engine that has been running for decades, with not the best oil changes. I would try and get some rags, something that does not let out small fibers, and very carefully clean as much of the gunk and caked on oil that is there before I closed it back up, clean the insides of the valve covers. If you end up pulling the pushrods, you might as well pull the rockers and clean them all before you put them back in. Also clean the oil passages in the pushrods, and the rockers. If you do pull the pushrods and rocker arms make sure to oil them thoroughly before you put them back on. Check the oil drain passages in the cylinder head to make sure that they are clear of any debris.
After it is all back together I would give than engine a nice oil flush treatment, put new oil in it, and then change the oil at more than normal intervals to try and remove as much of the gunked up oil that is in it as possible. Modern oils have a lot of detergents and just changing the oil more often than necessary will clean the engine up.