I was checking the local craigslist when i found this http://www.tlsperformance.com/trdlsdkalisl.html

It says it will fit 96-06 V6 models of the tacoma, but doesnt say it fits the 4Cyl?
Do the V6 and 4Cyl have different axels?

 

the 4 cyl has only 2 pinions, i think. but the number of splines are both 30

 

Different diffs and gearsets, not compatible. You could however, buy a V6 diff (cheap, assuming you have common stock gear ratios) and install the LSD into that diff which will bolt in to your diff housing without modification.

I don't think I'd go to all that trouble for a LSD though, they're not that useful for off road usage, more for street/track usage.

 

It WILL fit (assuming you don't have the TRD e-locker).

All 6-lug 1995.5 - 2004 Tacomas (except for those with the TRD e-locker) use the larger heavier differential commonly (and mistakenly) referred to as the '8.4'. This is the same '8.4' used in early Tundras and T100's (as well as 5-lug 2WD V6 Tacomas).

However ... As already mentioned, an LSD may be a questionable add-on for off-roading purposes.