No the rear axle code should be on the vehicle certification label. door jam?

Anyhow the rear axle should have a label on it stating 4_30 or 4L30 for limited slip. Based on your rpms I'm thinking now that it has the 4.30s

Whats the rpm at 75? What size tires do you have?



VEHICLE CERTIFICATION LABEL:

Exterior paint codes may be listed as a two-part code. The first set of characters listed indicate the vehicle primary body color code. The second set of characters listed (if applicable) indicated a two-tone or accent body color code.
AQ — Arizona Beige (clear coat), F-Series
BY — School Bus Yellow, Mexico sold only, F-Series
CX — Dark Shadow Gray (clear coat), F-Series
F1 — Vermilion Red (clear coat), F-Series
EP — Vermilion Red Solid, Mexico sold only, F-Series
FN — Dark Toreador Red, F-Series
GX — Dark Toreador Red, Mexico sold only, F-Series
L2 — True Blue (clear coat)
LR — Sapphire Blue (clear coat), F-Series
PB — Jewel Green, Mexico sold only, F-Series
PK — Chesapeake Blue, Mexico sold only, F-Series
PY — Highland Green (waterborne), F-Series
UD — Ebony, F-Series
TX — Bright Silver, Mexico sold only, F-Series
YO — Oxford White, Mexico sold only, F-Series
Z1 — Oxford White, Mexico build U.S. sold, F-Series
Z1 — Oxford White (clear coat), F-Series
Z3 — Silver Metallic (clear coat), F-Series
FL — Toreador Red, Excursion
JP — Silver Birch Metallic, Excursion
LD — Medium Wedgewood Blue, Excursion
P5 — Aspen Green, Excursion
ST — Estate Green, Excursion
TK — Mineral Gray, Excursion
UA — Ebony, Excursion
YZ — Oxford White, Excursion

Wheelbase
137 — 137-inch wheelbase (F-Series, Excursion)
141 — 141-inch wheelbase (F-Series)
142 — 142-inch wheelbase (F-Series)
156 — 156-inch wheelbase (F-Series)
158 — 158-inch wheelbase (F-Series)
162 — 162-inch wheelbase (F-Series)
165 — 165-inch wheelbase (F-Series)
172 — 172-inch wheelbase (F-Series)
176 — 176-inch wheelbase (F-Series)
189 — 189-inch wheelbase (F-Series)
200 — 200-inch wheelbase (F-Series)
201 — 201-inch wheelbase (F-Series)

Brake Type
B — Four-wheel anti-lock brakes system (ABS)

Interior trim codes are listed as a two-part code. The first character listed identifies the trim type. The second character listed identifies the interior trim color.

Interior Trim Type
K — Knitted vinyl bench seat, F-Series
C — Cloth bench seat, F-Series
F — Cloth captains chairs, Excursion
F — Flight bench seat, Mexico sold F-Series XLT only
G — High back cloth individual seats, F-Series
H — High back knitted vinyl individual seats, F-Series
J — High back vinyl individual seats, F-Series
3 — Cloth 40/20/40 seats, F-Series/Excursion
D — Cloth 40/20/40 seats with integrated restraints, F-Series
8 — Leather 40/20/40 seats, F-Series
9 — Leather 40/20/40 seats with integrated restraints, F-Series
2 — Cloth captains chairs, F-Series
6 — Cloth captains chairs with integrated restraints, F-Series
4 — Leather captains chairs, F-Series/Excursion
7 — Leather captains chairs with integrated restraints, F-Series
5 — Leather quad captains chairs, F-Series
L — Leather captains chairs, Excursion Limited
B —Leather captains chairs with vinyl rear bench, F-Series
M—Cloth 40/20/40 seats with rear bench mono. F-Series
P—Leather captains chairs with vinyl rear bench, F-Series
Interior Trim Color
H — Medium Parchment, F-Series
E — Medium Flint, F-Series/Excursion
B—Ebony, F-Series
D—Dark Flint, F-Series

Tape/Paint Stripe (TP/PS)
D — Light Argent/Medium Platinum/Light Argent, F-Series XLT
E — Arizona Beige/Dark Sandalwood/Arizona Beige, F-Series
F — Wild Strawberry/Dark Shadow Gray/Wild Strawberry, F-Series

Radio Type
7 — AM/FM stereo with clock, F-Series
G — Delete AM/FM stereo with clock, all other components installed, F-Series
9 — AM/FM stereo with cassette and clock, F-Series/Excursion
R — Delete AM/FM stereo with cassette and clock, all other components installed, F-Series
K — AM/FM stereo with cassette and compact disc player, F-Series/Excursion
Y — Delete standard AM radio with clock, F-Series
1 — AM/FM stereo with cassette and in-dash six disc compact disc (CD) changer, F-Series/Excursion

Axle Type
61 — 3.73 non-limited slip, F-350 (dual rear wheels)
F1 — 3.73 limited slip, F-350 (dual rear wheels)
62 — 4.10 non-limited slip, F-350 (dual rear wheels)
F2 — 4.10 limited slip, F-350 (dual rear wheels)
63 — 4.30 non-limited slip, F-350 (dual rear wheels)
66 — 4.56 non-limited slip, F-350 (dual rear wheels)
F6 — 4.56 limited slip, F-350 (dual rear wheels)
81 — 3.73 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E1 — 3.73 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
82 — 4.10 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E2 — 4.10 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
83 — 4.30 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E3 — 4.30 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
86 — 4.56 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
E6 — 4.56 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
88 — 4.88 non-limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
EW — 4.88 limited slip, F-350 Chassis Cab, narrow frame (dual rear wheels)
G3 — 4.30 limited slip, F-450 Chassis Cab
73 — 4.30 non-limited slip, F-450 Chassis Cab
78 — 4.88 non-limited slip, F-450 Chassis Cab
G8 — 4.88 limited slip, F-450 Chassis Cab
75 — 5.38 non-limited slip, F-450 Chassis Cab
G5 — 5.38 limited slip, F-450 Chassis Cab
GW — 4.10 limited slip, F-450 Chassis Cab
98 — 4.88 non-limited slip, F-550 Chassis Cab
K8 — 4.88 limited slip, F-550 Chassis Cab
95 — 5.38 non-limited slip, F-550 Chassis Cab
K5 — 5.38 limited slip, F-550 Chassis Cab
KW — 4.10 limited slip, F-550 Chassis Cab

Transmission Type
E — Four-speed automatic overdrive (4R100), gasoline engines, F-Series/Excursion
9 — Four-speed automatic overdrive (4R100), diesel engine, F-Series/Excursion
6 — Six-speed manual, Dana ZF (M6HD-6), F-Series
5 — Six-speed manual, F-Series (5.4L, 6.8L Gas)
2 — Five-speed manual, F-Series (5.4L, 6.8L Gas/LPG), Mexico only

 

dang. thats alot of info and very much appreciated. thanks. i'll look into to it tonight

 

well i looked and all i found for axle was "4N" but i don't see it in the list

 

You have a 4.10 limited slip


The newer 2005-2006 use these codes:



37- 3.73

3L- 3.73 LS

41- 4.10

4N- 4.10 LS

43- 4.30

4L- 4.30 LS

48- 4.88

8L- 4.88 LS

53- 5.38

5L- 5.38 LS

 

ok thanks yeah i saw the 4.10 on the diff plate. well thanks for all the help again. sorry for hijacking,