ke-25 rolla 3t crank will fit in a 2t block, 2t block has narrower crankcase skirts than 3t. 3t crank in a2t block you will punch ahole in side of block. 2tg head will fit a 3t block you will,need timing cover, timing chains,chain idle pully,dummy camshaft that drives distributorand fuel pump. if you do this youwill need to knock out the last two cam bearings in the 3t block turn 180 degrees knock back in to stop lost oil pressure. 2t-1600 bore 88.5 mm-1750 3t-1770 bore 88.5-1980. when you adjust the valves in the head if it is off the motor, do it one cam at a time other wise you will bend valaes on overlap
cheers mick