Gentlemen I am replacing the gas gauge sending unit in my 1956 Mercury Montclair. What position does it go in? the float facing the rear bumper or towards the front of the car? Possible perpendicular? Even the large not to be named parts company I bought it from knows. Thank You inadvance

JohnnyB
All the tanks that I've installed sending units into want the float to be side to side, not to front or rear.
Example would be if the mounting hole is offset to one side, the float arm is to be toward the other side.
Make sense?
Jim

Kahuna, TY but the mounting hole is in the center of the tank. So are you suggesting it goes the shorter way of the tank? Reference would be from rear wheel to rear wheel? TY JB

Kahuna is correct.  With float oriented side to side the gauge will  read more stable.  Other wise, when going up or down hills, accelerating or braking the fuel level would fluctuate up and down.
 

Ben HessTulsa,OK

My 56 Ford is to the rear and it's not been a problem. I've had it out many times. It does not react very quickly but I don't remember it being a problem in 56 and it isn't now..Good Luck.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

TY one and all. Unless I find the guy who worked the line and installed them when building the car we will never know. But I will try the side to side method because that makes the most sense to me.

Johnny B - I though I would offer a few comments concerning your fuel gauge sender.  Comments are based on my experiences with my 56 Ford Victoria, which takes the same Sender as the 56 Mercury Monterey. Not sure about the 56 Mercury Montclair.  If the Montclair's fuel tank capacity is greater than the Ford 17 gallons, then its Sender is probably different.  The bolt (screw) spacing on my original Sender (as well as on several "replica" senders I have tried) is unequally spaced. This means the Sender will attach to the tank in only one position. That one position is with the float toward the rear of the car. This would place the float at or near the fore and aft center of the tank, so any fore and aft acceleration of the car would have no or little effect on the fuel level.  If the float were placed to one side of the tank, the fuel level would change when going around a curve. 

You mentioned that you have obtained a new Sender, which I assume is a replica.  All of the replicas I know of are nothing more than a variable electrical resistor (rehostat) which sends a continuous current to the gauge which varies with fuel level.  The original King Seeley system was not designed to work this way.  It sends an on/off current to the gauge where the "on" time increases with fuel level.  With a continuous current applied to the gauge, only 3 volts are required for the gauge to read 1/2 full.  In fact, this is a method for checking the gauge as described in the 1956 Ford Service Manual, as well as Motors Repair Manuals which cover that era.  These manuals also describe the operating principle of the King Seeley original system. With only a continuous 3 volts required to read 1/2 tank (and less for less than 1/2), the replica gauges are inaccurate - especially for lower readings when you need accuracy the most. I WOULD BE VERY INTERESTED ON HOW YOUR SENDER WORKS OUT FOR YOU.   BTW, I noticed an original Sender on eBay (item 252271720742).  You don't often see them available anymore.  "Only" $350. !!!  (No, I'm not the person listing it). 

Bill Newland