[Kolton5543]

So the 70s 305 died Friday. it ran good for maybe two days. The first time I went for a longer drive where it would get a good heat soak at higher speeds (about 15 miles) it started making some questionable noises. I took it to a friends house and looked at it briefly and set the base timing (why I drove it there). We didn't find the source of the noise but it sounded deep. On my way back home it started getting louder then a bit of squealing. After about two minutes of that it started loosing power then came to stop. It will still crank but super slow. The bottom end is not liking something. I suspect the killer was a combo of the balancer was not centered on the crank and it looks like the oil drains in the head may be a bit clogged and pumped all the oil into the heads and valley. I'll try to get it torn down and see what failed in the next day or two.

Good new is I had managed to possibly fix the 350. It made very low compression on 3 cylinders and one cylinder was locked on coolant. The engine was rebuilt with a .020" over bore and it has a tag from the builder. I pulled the heads to see what condition it was in and found the bores to be in near perfect shape. The cross hatching was still clearly visible. I suspected blown head gaskets from the low compression but the looked perfect. After further inspection I realized only the bottom end was rebuilt and the untouched heads were reused. I then noticed the exhaust valve on cylinder 1 was sunk into the seat being nearly flush with the surface of the combustion chamber. Cylinder 1 also made only around 30psi dry. I filled the chambers with ATF and found that every valve leaked some and the low compression cylinders leaked almost everything out of the exhaust valves. I then found that the coolant was entering the cylinder from a crack within the intake runner. I took apart the water pump and the impeller separated the from the shaft so my assumption is heat was the killer. The cam and lifters look to be in great shape so that gives me hope the crank and rod bearing are still good. Checked the deck for flatness and bolted the TBI 305 heads and checked compression and it brought all the cylinders back to good compression. After doing the math my compression ratio is going to be about 9.7 with the smaller chambers and the gaskets I had laying around so hopefully it'll run ok on cheap gas. I'm crossing my fingers that the hydro locked cylinder didn't wreck the bearing. I didn't find anything in the pan that looked concerning and the oil was in good shape. Im hoping to get it running and in the truck by tonight. Normally I would just take a bit more time on it but I have to get it going before I have to move again and that time is coming quick.