97 chevy service truck bent pushrod

not really big truck or even diesel (Chevy 350 vortec) but i know a lot of you are very knowledgeable in more than just one aspect of turning wrenches.

i recently bought a service truck, got it cheap. runs rough seller claimed blown head gasket, said they had it looked at no compression on #6. i asked if one of the adjacent cyl's had no compression as well (ie head gasket blown threw the fire ring between two adjacent cyl's) they said they didn't believe so but didn't know if they might have just stopped with the compression test on #6 anyway the price was cheap enough i figured even with putting a new motor in it was still a good deal. trans shifts good 4wd works a/c even blows cold ect.

get it back to my shop and do my own compression test and find 0 compression on #6 all adjacent cyl's between 155-160 so i pull the valve cover and find a bent push rod on the #6 exhaust valve. the exhaust valve also seems to be stuck part way open (most likely bent)

so my question is what is the likely hood of piston damage? any opinions on course of repair ie rebuild the existing motor, used replacement, rebuilt crate engine. pull the head inspect the piston replace the valve and put it back together?

i don't intend to put many annual miles on this vehicle if that makes any difference

also the engine runs surprisingly well for only running on 7 of 8 cyl's other than a rough idle and low power.

any idea what might have caused this? iv rebiult a motor or two due to low compression burning oil ect, never had one do this before, other than one where a timing belt snapped and shoved a bunch of valves into pistons and punched holes in the pistons and caused all kinds of carnage, obviously not what happened here.

 

a few pictures of the truck




bent pushrod

 

i pulled the valve cover and found a bent push rod #6 exaust, and either a stuck/bent exhaust valve on #6, at witch point i removed the bent pushrod put the valve covers back on spark plugs back in and pulled it outside till i get a bit more time to mess with it.

iv never seen just one valve/pushrod bent, only times iv personally come across it was normally caused by a catastrophic failure in the valve train and wide spread carnage this seems to just be the #6 exhaust valve. all other cyl's have 155-160 psi and everything looks good truck has 200k on it

 

i did some calling around today and i might have found a good used engine. they say its still in the truck i can come hear it run in a 99 suburban before they pull it. $350 bucks and they will pull it for me. that just might be the way to go. swap it out and then throw the motor from the service truck on the engine stand and rebuild it. never hurts to have a fresh Chevy 350 laying around.

id rather not have a whole truck sitting in my way for long if i swap the motor it will take less time from tear down to back running again, then i can rebuild the motor at my leisure and if the used motor goes i can throw the rebuilt back in.