I have a small block 307, hydraulic lifters, flat tappet cam. and its all stock except for a intake manifold and carb. I just toke a trip to lime rock in my car it was alittle over an hour away each way. On the way back i was 10 minutes away from home and i noticed a odd noise so i pulled into a parking lot to check it out, Its alittle hard to identify but it almost sound like a chirping, its like high pitched noise. It seems to be coming from the passenger side rear of the motor. It was pretty hot and the oil was pretty thin being so heated up. The oil was kind of low but it shouldnt of affected it. I pulled the passenger valve cover off to see if anything looked out of the ordinary but i didnt notice anything. Any ideas?