I broke a valve spring and bent a push rod in my 5.9 R/T.It didn't hurt anything other than the push rod.I was about 5 miles from my brothers shop when it broke so I drove it there missing and making lots of noise.After 1 of the stock springs broke I replaced all of them with the MP.525 springs.

 

they might use air, they might use rope to hold the valve up.
if the valve or seat is damaged, it might leak.
you'll want to do a compression test afterwards to know what your engine status is.

bent push rod will cause the valve not to open.
broken valve spring "might" cause it not to close up.
if intake valve is working and drawing in fuel, and exhaust valve is staying open it will allow the fuel to escape on the compression stroke and yes it does flow into the exhaust, cat, muffler.

lots of unknowns. i wouldn't try to overthink it. just fix the 2 known problems and see if it'll run right.