Hello After spending a long time reading the coolant change threads I'm concerned that the generally recommended draining of half (or less) of coolant from radiators (followed by vacuum re-fill) may not be a best solution due to potential incompatibility of fluids (OAT/HOAT/IAT etc) - it's difficult to be sure about the type of fluid put in under the previous ownership. Even with multiple distilled water flushes, it would still be better to drain the block as well (I think). So where are the 2 drain holes in the engine block? One post says that the left side is easier to access and removes most of the fluid, so that would be a good place to start. Also is there a way to push-out the old fluid by pushing in the fresh one, similarly to pressure changing brake fluid? I can't think of any without thermostat removal, and removing the thermostat would probably be too much work comparing to just draining.