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The Hitach H150 differential was fitted to 1975-up Sunny. It has a 150mm (5.91 inch) ring gear, so is stronger than the H145 that was fitted to previous models. H150 is strong enough to handle the torque from A14 and A15 engines. Datsun used the H150 for all A14-powered cars.
Ratios
3.889 replaced the H145 3.90. The ratio allowed for quieter gears.
3.70
3.545 is listed in the catalog as being for:
- AUTO(CAL),A12 from Aug 80 [i.e. 1979 model and newer]
- MANUAL(A14,MPG) from Aug 80
- MANUAL(A15,MPG) from Dec 1979 to July 1980 [1980 model only]
Swap Into H145 Housing
The easiest swap is to get the entire rear-axle assembly from a 1975 or newer B210 with A14 (140Y) -- this is the H150 (150mm diameter ring gear). The main spring is 55mm longer, but the others can be used on the 1200.
See Bolts right in!
Japan diff
NOTE: The 1974 B210 uses an H145, although the housing is the new stronger design. H145 can be distinguished by studs, whereas H150 uses bolts to fasten the diff to the case.
B210s have a strong axle housing (axles tubes are larger, to 2.2 inch up from 2.0 inch, so U-bolts are different). The B210s use an isolation clamp (the axle tube is rubber mounted), and so the mounting pad is wider. You will need the clamps, u-bolts and shock mounts to do a swap. The housing also user larger ball 72x32x19 bearings (up from 62x32x16) with both inside and outside seals. The B110 only had one seal.
Because the H150 is longer, the driveshaft is shortened by 7mm. The housing face is 2mm toward front of car (diff gear is 5mm larger)
Datsun Competition (later Nismo) used to sell various ratios: 3.545, 3.7, 3.9, 4.111 for the H150.
Whilst NISMO produced H150 LSDs (Limited-Slip Differential), Axles baffles and Oil Coolers were not available from Nissan for the H150.
Good for maybe 125 lb. ft. of torque
You can also just put the H150 gear assembly in the stock H145 axle housing. You just need a 2mm spacer:
Pitroad Spacer
Use a B310 propeller shaft with H150 diff in B110.