Why, oh why did GM think it was a good idea to use phenolic as a gear material in their timing gears???? Literally the morning after I got my AC running again (its been 6 years since I've had working AC) this happened. I fired the truck up to check to see if the AC had leaked over night, it ran like CRAP for about 2 minutes then died. I tried to restart it, and it spun over like it had ZERO compression... Uh oh... Yes, I have bent pushrods. I pulled them all out so all the valves *should* be closed. I'm going to do a compression and leakdown test tonight (pull all the plugs and just turn the crank) to see if the valves are toast. They probably are. FML. 1986 Chevy C30 454 with around 153,000 on it. I'm pretty sure it's all original. So far everything I have seen in the engine looks OEM original.