[67C10Step]

Had the same thing happen to my 70 model with a 350 back in college. Roommate and I jumped in the truck to go grab a pizza. Pop, pop, pop through the carb. Looked at my buddy and said, "We better take yours. I think I just dropped a rocker arm." Turns out I was correct. Got him to run me to the parts store and fixed it up later that day. Drove that truck another 3 years at least.