A gauge like that uses a sending unit that threads into the intake manifold and is usually permanently mounted in the car, usually under the dash, the signal from the sending unit is carried to the gauge by a wire, it is not possible to thread it directly into the engine. Where is the sending unit located that you are using right now? Ive never seen an autometer used as a temporary gauge, but Im sure you could make something work, kind of pricey though for something that would only be used briefly.