Ok, here's the deal... I had the original 283 in my wife's 58' rebuilt. When I put it back in, I also swapped out the original cast iron PG for a TH350. I got the transmission from my Dad, who got it in a trade. It was supposedly rebuilt. Before I put it in, I replaced the front & rear seals. I also pulled the pan and replaced the filter just in case. I used a new converter as well. It looked very clean inside so I decided to run it. I've got most of the bugs worked out, but there's an intermittent chirping sound coming from the back if the engine. At first I thought it was the linkage jingling on the transmission but it's not. It happens in park, neutral, or in gear. But not all the time. It increases with RPMs. Sometimes it doesn't make the noise at all. This afternoon I put the car on ramps and let it run for a while. When the noise started, it seemed like it was coming from the crankshaft near the rear seal or maybe near the torque converter. I sprayed a shot of WD-40 on the crank at the seal and it seemed like it stopped but I'm not sure. It started again again a few minutes later then went away on it's own. The flex plate and bolts are new. Everything is tight and I used loctite. Any ideas? Posted using the Full Custom H.A.M.B. App!