3" heat exchanger mounts
There are two different styles of mounting brackets used on the 3" Heat exchanger. The first style has a pair of steel brackets soldered to the brass casing. With time and vibration the brackets tend to break off. The standard repair is to have the brackets reattached, some use a radiator shop, I chose to have mine brazed on for added strength. I am also going to add hose clamps for additional support to this critical component (not shown in picture). Also visible on the left side of the heat exchanger is the hex shaped threaded collar where the pencil zinc is inserted.
The critical dimension is the one between the bolt holes. The measurement for the M25xp engine is 6 3/8". The brackets used on newer heat exhangers go all the way around the heat exchanger and have a clamp bolt incorporated.