The 108 variants closely resemble each other but can be visually distinguished by their design changes:
Prototype 108
Two prototype model 108s were converted from Stinson model 10A airframes.
FAA records show NX31519 was model 108 serial number 1, and NX31532 is model 108 serial number 2.
 Both registrations later changed to NC.
The production model straight 108 would also use serial number 1 and 2, so there was for a short period 2 duplicate serial numbers;
108 Voyager 125
Powered by a 125 hp (93 kW) Lycoming O-235 piston engine.

108 Voyager 150
Powered by a 150 hp (112 kW) Franklin 6A4-150-B31, B3 or B4 piston engine.
742 built in 1946.

108-1
Slightly modified version with external baggage door.
1508 built 1947–1948.

108-2
Powered by 165 hp (123 kW) Franklin 6A4-165-B3 or -B5.
1250 built from May 1948.
There was a conversion kit to add the rudder trim to the earlier airplanes advertised.

108-3
The 108-3 introduced a taller vertical fin with a rudder featuring a straight trailing edge.
Larger fuel tanks (50 U.S. gallons (190 L; 42 imp gal) versus 40 U.S. gallons (150 L; 33 imp gal)) were also fitted.
The -3 has a higher gross weight than its predecessors of 2,400 lb (1,089 kg).
1760 built by Stinson and Piper.

108-4
The 108-4 was a higher powered model 108, sn 108-4693, NX149C, not certified, flown experimentally by Stinson, later by Piper, 1 built.

Flying Station Wagon
The "Flying Station Wagon" version was an option available with the -1, -2 and -3 models, had a utility interior  incorporated wood paneling and a reinforced floor, allowing 600 lb (272 kg) of baggage in the passenger compartment.
The aircraft could be fitted with wheel, float or ski landing gear.
The single 108-4 built was a Flying Station Wagon.

108-5
A single 108-5 was built by Univair, who purchased the Stinson 108 type certificate from Piper, in 1964.
The 108-5 used a 180 hp (134 kW) Franklin 6A-335-B1 engine.
Univair offered kits to convert earlier aircraft to this standard.
The 108-5 brought total model 108 production to 5,261, of which 5,135 were built by Stinson, 125 by Piper, and 1 by Univair.
The 108 variants closely resemble each other but can be visually distinguished by their design changes:
Prototype 108
Two prototype model 108s were converted from Stinson model 10A airframes. FAA records show NX31519 was model 108 serial number 1, and NX31532 is model 108 serial number 2.  Both registrations later changed to NC. The production model straight 108 would also use serial number 1 and 2, so there was for a short period 2 duplicate serial numbers;
108 Voyager 125
Powered by a 125 hp (93 kW) Lycoming O-235 piston engine.
108 Voyager 150
Powered by a 150 hp (112 kW) Franklin 6A4-150-B31, B3 or B4 piston engine. 742 built in 1946.
108-1
Slightly modified version with external baggage door. 1508 built 1947–1948.
108-2
Powered by 165 hp (123 kW) Franklin 6A4-165-B3 or -B5. 1250 built from May 1948. There was a conversion kit to add the rudder trim to the earlier airplanes advertised.
108-3
The 108-3 introduced a taller vertical fin with a rudder featuring a straight trailing edge. Larger fuel tanks (50 U.S. gallons (190 L; 42 imp gal) versus 40 U.S. gallons (150 L; 33 imp gal)) were also fitted. The -3 has a higher gross weight than its predecessors of 2,400 lb (1,089 kg). 1760 built by Stinson and Piper.
108-4
The 108-4 was a higher powered model 108, sn 108-4693, NX149C, not certified, flown experimentally by Stinson, later by Piper, 1 built.
Flying Station Wagon
The "Flying Station Wagon" version was an option available with the -1, -2 and -3 models, had a utility interior  incorporated wood paneling and a reinforced floor, allowing 600 lb (272 kg) of baggage in the passenger compartment. The aircraft could be fitted with wheel, float or ski landing gear. The single 108-4 built was a Flying Station Wagon.
108-5
A single 108-5 was built by Univair, who purchased the Stinson 108 type certificate from Piper, in 1964. The 108-5 used a 180 hp (134 kW) Franklin 6A-335-B1 engine. Univair offered kits to convert earlier aircraft to this standard. The 108-5 brought total model 108 production to 5,261, of which 5,135 were built by Stinson, 125 by Piper, and 1 by Univair.
Stinson 108