Java Edition:Invalid Lava Level in the Overworld
Liquids in minecraft are using level block state to determine the level of the liquids, with values from 1 to 7, 1 being the shortest. Before version 14w25a data values are used where scale is reversed; for example data value of 3 is an equivalent of level 5. To make a lava stream in the overworld appear shorter, odd values are skipped, making even values normally not obtainable in that dimension.
Obtaining
Infdev Liquid System
From Infdev 20100327 to Infdev 20100615 odd data values of lava weren't skipped when it was flowing. Meaning lava could flow as far as water, a whole 8 blocks. After upgrading, assuming the lava stream isn't updated by anything, the lava stream will stay 8 blocks long, or shorter if it had been blocked off from flowing further when originally created.
Tripwire Transmutation
Tripwire transmutation can be used to obtain data values of 5 and 7. Using door transmutation, already obtained lava blocks with data values of 5 and 7 can be lowered to 1 and 3.