Probably the M5OD-R2, I'd be changing it out for a ZF5, the only real advantage of the M5OD is that you have 4 speeds PLUS overdrive, If you want to keep the 4 speed plus overdrive you might want to switch to the ZF ment for deisle engins but you'll need an adapter plate, you might then not have a long enough input shaft, it might be too short to reach the pilot bearing. You might be able to change the internals out into the case designed for gasoline engins but I don't know, Any ZF5 experts out there?
Below is something I found a long time ago
Model: SROD (single rail OD)
Manufacture: Tremec
Type: Four speed overdrive w/ push down reverse
Years: 1978-83/4
Truck:
Engines: 300, 302/351
Construction features: Aluminum, synchronized in forward gears, shifter near back
Trans code: B
Gear ratios:
- 3.25, 1.92, 1.00, 0.78, 3.25 (300/302)
- 3.01, 1.78, 1.00, 0.78, 3.01 (351)
Model: TOD (top shift overdrive)
Manufacture: Tremec
Type: Four speed overdrive
Years: 1984-85
Truck: F100/F150/F250
Engines:
Construction features: Aluminum case and shift tower
Trans code: B
Gear ratios: 3.29, 1.84, 1.00, 0.69
Model: Tremec 3.03
Manu factor: Tremec
Type: Three speed non overdrive
Years:
Truck: F100/150/250
Engines: 240 (RAN), 300/360/390 (RAT)
Construction features: Cast iron case, top-loader design, syncro'd first gear, column shift
Trans code: C
Gear ratios:
- 2.42, 1.61, 1.00, 2.33
- 2.99, 1.75, 1.00, 3.17
- 3.41, 1.86, 1.00
Model: NP-435
Manufacture: New Process
Type: Four speed non overdrive
Years: 1965-90
Truck: F100/F150/250/350
Engines: 300, 302/351, 351/400
Construction features: Non syncro first gear, cast iron w/aluminum top plate, shifter in top, PTO Pass side
Trans code: A
Gear ratios: 6.69, 3.34, 1.79 or 1.66, 1.00
Model: T18
Manufacture: Borg-Warner
Type: Four speed non overdrive
Years: 1965-93
Truck: F100/F150/F250/F350
Engines: 300, 302/351, 460
Construction features: Non syncro first gear, case iron case, PTO port on passenger side
Trans code: F
Gear ratios: 6.32, 3.09, 1.69, 1.00
Model: T19
Manufacture: Borg-Warner
Type: Four speed non overdrive
Years: 1983-91
Truck: F250/350
Engines: 460, 6.9/7.3
Construction features: Full syncro, case iron, PTO port on both sides
Trans code: P
Gear ratios:
- 6.32, 3.09, 1.69, 1 (83-86 F250s with 460 and 4wd)
- 4.02, 2.4, 1.4, 1
- 5.1, 3.0, 1.8, 1
Model: T85
Manufacture: Borg-Warner
Type: Three speed non overdrive
Years: 1965-71
Truck:
Engines:
Construction features: Non-syncro first gear, case iron-side loaded case w/ 9 bolt cover
Trans code:
Gear ratios: 2.94, 1.94, 1.00
Model: T86G/H
Manufacture: Borg-Warner
Type: Three speed non overdrive
Years: 1957-64
Truck:
Engines: 223, 292
Construction features: Non-syncro first, cast iron case, shifter on the side
Trans code:
Gear ratios:
- 2.80, 1.69, 1.00, 0.70, 3.80 (G-6 cylinder)
- 2.57, 1.55, 1.00, 0.70, 3.49 (H-8 cylinder)
Model: T87
Manufacture: Borg-Warner
Type: Three speed non overdrive
Years: 1948-75
Truck: F250
Engines:
Construction features: Non-syncro first gear, case iron-top loaded case w/ 9 bolt cover
Trans code: E
Gear ratios:
Model: T89
Manufacture: Borg-Warner
Type: Three speed non overdrive
Years: 1956-71
Truck:
Engines:
Construction features: Non-syncro first gear, cast iron-top loaded case with 9-bolt side cover
Trans code: D
Gear ratios: 3.17, 1.75, 1.00, 3.76
Model: T98
Manufacture: Borg-Warner
Type: Four speed non overdrive
Years: 1948-64
Truck: F100/250
Engines:
Construction features: Cast iron
Trans code: F
Gear ratios: 6.40, 3.09, 1.69, 1.00, 7.82
Model: M5OD-R2 (M5R2)
Manufacture: Mazda
Type: Five speed overdrive
Years: 1988-96
Truck: F150 and F250LD
Engines: 300, 302
Construction features: Aluminum throughout, fully synronized, integrated bell housing
Trans code: M
Gear ratio: 3.91, 2.24, 1.49, 1.00, 0.80
Model: ZF S542/S547
Manufacture: ZF
Type: Five speed overdrive
Years: 1987-94 (S542) and 95+ (S547)
Truck: F250/350
Engines: 300, 351, 460, 6.9/7.3
Construction features: Aluminum throughout, fully synronized, integrated bell housing, PTO covers on both sides of case
Trans code: Z (88/9), C (88-97 close ratio), W (89-01 wide ratio)
Gear ratios:
- 5.72, 2,94, 1.61, 1.00, 0.78 (gas engines)
- 4.14, 2.37, 1.42, 1.00, 0.78 (diesel engines)
