4WHEELOFFROAD.COM 4-WHEEL & OFF-ROADOCTOBER 2019 33
DANA 20
Overview: A remarkably strong, compact
transfer case found in lot s of 4x4s from the
1960s and 1970s.
Found In: 1963-1979 Jeep vehicles;
1965-1979 International Harvester; 1966-
1977 Ford Broncos; some rare 1969 -1973
Chevy Blazers.
Identification: Jeep: Look for the Texas
pattern on the front of the case with an off-
set front output and centered rear output.
Ford: Driver drop with six-hole front pattern
with flat inspection cover plate.
Low-Range Ratios: Jeep: 2.03:1; Ford
J -shif t : 2. 34:1; Ford T-shif t : 2.46:1
Modifications: Low-range gears, heavy-
duty output shafts and rear housings, twin
stick shifters.
DANA 20DANA 300
Overview: The strongest transfer case
ever offered in an open-top Jeep, the Dana
300 comes with the lowest factory low
range of the cast iron/steel cases.
Found In: 1980-1986 Jeep CJs; 1980
International Harvester Scouts (one year
only with a Texas front pattern).
Identification: Jeep six- hole front pat-
tern, cast iron/steel case with offset front
output and center rear output, aluminum
shift tower, and aluminum front and rear
bearing retainers.
Low-Range Ratio: 2.62:1
Modifications: Low-range gears, heavy-
duty output shafts and rear housings, twin
stick shifters.DANA 300Found In: 1941-1971 Willys/Jeep vehi-
cles; 1966-1972 International Harvester
Scouts.
Identification: “Texas” mounting pattern
on the front of the case (you’ll know what
we mean when you see it). Offset front and
rear outputs.
Low-Range Ratios: 1.97:1 (WWII jeep
with ¾-inch intermediate shaft); 2.43:1
(1946 with 1^1 ⁄ 8 -inch shaft); 2.46:1 (1946-
1971 with 1¼-inch intermediate shaft.
Modifications: Can be modified to run an
ex ternal P TO and/or have an ex ternal over-
drive like a Warn/Saturn OD. Can be modi-
fied with gear ratios lower than factory via
slight case modification and installation of
aftermarket gears. Many adapters are avail-
able, including a divorce mount input with a
yoke. Spicer 18 guts can be swapped into a
Dana 20 case for the strongest 18 possible.
NP205
Overview: This is the big boy transfer
case, a heavy-duty light-duty T-case. The
strongest unit you can get without buying
an aftermarket transfer case.
Found In: Some full size GM , Ford , and
Dodge 4x4s.
Identification: Cast iron/steel case with
aluminum bearing retainers at front and
rear outputs. Both driver and passenger
drop with various input and output differ-
ences, including slip-yoke rear on some
cases and some divorced cases with a yoke
on the input. Smallish centrally located rear
idler shaft cover with three bolts holding it
to the main housing. Most 205s have an ID
tag riveted to the housing.
Low-Range Ratio: 1.96:1Modifications: Heav y- duty input s and
front and rear outputs, and twin stick shift-
ers. JB Conversions used to make 3.0:1 gears
for the NP 205 in small batches and may
again. Offroad Design makes a Magnum low-
range box that bolts to the front of an NP205
and yields 1:1, 1.96:1, 2.72:1, and 5.33:1.NP205NP203
Overview: Worth a mention because it’s
a fairly common unit in full size 4x4s and the
low-range box (first part of the case) can
be mated to other transfer cases to serve
as a “doubler” case, effectively creating a
three-speed transfer case.
Found In: Some fullsize GM, Ford, and
Dodge 4x4s.
Identification: Huge four-piece design.
The first two (range box and chain hous-
ing) are cast iron/steel, and the rear two
parts (differential and output housing) are
aluminum.
Low-Range Ratio: 2.01:1
Modifications: Keep the low-range box
and bolt it to the front of an NP205, Dana 300,
or anything that will stand the extra strain.
Offroad Design makes doubler adapters to
mate an NP203 range box on an NP205.NP203