There is a chance that a early 60's truck will fit..will have to change you face on the gauge...however..for my money I would stick with the old style and adapt it to the 318..just get a 15.00 nice gauge of the thermo bulb style, graft the head of the old on the tube of the new..wha lah..you have your original dash, new bulb, longer line, new engine fittings...no future headaches..
This is what I am doing with the 41 and the 383 I have installed. Plus..you can calibrate the mechanical gauge after conversion for accuracy.