The thread is indeed 3/4

The filter sizes are different depending on if the car is 2wd or 4x4. This is down to the different engine crossmembers and engine mounts, and lack of clearance between the filter and 4x4 engine mount. The 4x4 oil filter mounts remotely on an arm to the rear of the engine mount, whereas the 2wd filter bolts straight on to the block with the modine (water-oil cooler) sandwiched in between.