I'm doing an experiment. I was an imported auto technician for thirty years and would never use a head gasket sealer for my customers. I picked up a 93 Land Cruiser that overheated. I runs perfect but has white smoke from the exhaust. I bought all the stuff for doing the head gasket and as I was taking it apart I found that the alternator was seized so the belts weren't spinning the water pump. I did a compression test and all the cylinders were about 200-220 psi and the plugs looked the same and hardly worn. I put a new alternator in and started it up with a radiator pressure tester installed. Ran perfect with the exception of the white smoke from the exhaust. It did not overheat ( temp gauge right in the middle) and the pressure held steady at 10 psi. After shutting it off the pressure held fine and eventually dropped to zero after 45 minutes. So I did a lot of research on head gasket sealers and Steel Seal had tons of good reviews and was by far the most expensive. So I ordered a bottle and I'm going to try it. I will post updates on how it works and for how long. I'll hold on to all the new parts so when it fails I'll replace everything with OEM gasket set, arb studs and aisin water pump.