John, the 18mfd (54) pos to cathode/heater 5Y3G or plate of 6C5G (most likely 5Y3G) neg to chasis gnd, the 16mfd (56)pos goes to cathode/heater 5Y3G, neg to HV center tap. Do not connect 56 to chasis gnd, the can (if it's in one) should be isolated (insulated)from chasis by some method. PL
:On my Fairbanks-Morse Model 8A I'm not sure what the polarity of the electrolytics 5A and 56 as I want to replace them. It seems that 5A should have negative going to ground but I'm not sure about 56 at all.