comparing going from a 3k to a 3t in a ke25
instead of 3k to 4k is like comparing chalk and cheese.
3T will require, new engine mounts, gbox mounts, hydraulic clutch conversion etc etc.
a 4k will bolt straight in, a very cheap and effective upgrade as long as the engine is in good condition.
punchy throw a 4k in there, get ur weber jetted to suit and have some cheap fun.
cheers, scott