Well I hate to throw another wrench into this but many folks, including me, would love to have any Chevy V8 Built in 1972 or earlier. These are the motors with the most HP per their cu in. Anti smog/pollution requirements started in 1973. Motors were "redesigned" and loss HP over night. If the 350 is actually a 1972, by looking at casting numbers and the serial code (application code) stamped on the head pad in front of and below passenger valve cover, that would be a nice motor to have.
A screw driver won't get it as you have discovered. Use a long wooden dowel or an extension handle from a paint roller or other household handle. Place one end all around the motor and the other end cupped to your ear. Touching your ear.
Hard to say about your motor. Seems like you said it does not knock right away, but after warm up. After parts expand possibly. Also the knock may be a separate issue than the smoke. Not sure. When did you notice each issue? Was motor OK for awhile, weeks, months, then not OK? You say you "worked on it some more" then it developed the knock and smoke? Can you clarify that?
here is the story of the past issues (sorry its long). I bought the truck a couple months ago, as is, and later found it had some power issues. It bogged down under harder acceleration and under load up hills. When I say bogged down, I mean it literally lost power and limps until the load went off and then slowly recovered as the load decreased, although i'd limp it back home. I didn't see the tach rev, so its not a tranny slipping. Have been slowly fixing small things here and there, rebuilt the carb, and then put new plugs, wires, fuse line and filter, and tuned it up. I also noticed the oil pressure would be at 50 on start up, but as I drove it, it seemed to drop right off when I stopped at traffic lights - almost down to zero. It would come to 25 - 35 easily as soon as I started to drive. But obviously I noted it dropped oil pressure after start up. It didn't burn oil. It has a 700R4 so I spent some time ensuring the TV cable was adjusted and shifting correctly (put a new, better aligned bracket for it on) to eliminate the transmission. In any case, after the new bracket and TV cable adjustment I took it for a test drive yesterday down a quiet road - about 25 minutes worth after it already warmed up in the driveway, Tranny shifts good now. Tried again to accelerate and it seems good, then started to stumble, although it did get to 60 mph before it did it. Seemed like good acceleration to that point too. Headed for home and it really started to loose power up a small incline in the road (going about 25mph at that time as its got some sharp bends). So I parked in the driveway and checked the tuning again (no knocking then but perhaps a little more noise on drivers side) and revved it to 2500 - 3000 in the driveway to check advance. All good - turned engine off and then tightened distributor bolt, started it back up - and it started the loud knock. Also still saw the moisture on the ground behind the exhaust, so revved it and I see some whitish smoke. It should have been good and warm at this time.
I'd thought the loss of power was a fuel delivery issue or running lean. Ive pulled those out and my suspicion of a worn engine was confirmed in my mind with the knock and the white smoke, and the unsteady oil pressure . I know there are lots of variables, so let me know your thoughts.
