Thanks for the info, but as I said this block has no markings, so can't tell by that. Has 5MGE intake manifolding, pistons are forged Arias and rods are Carillos so can't look at those and tell size etc without tearing motor down. Block has no machining inside. Was after a dimensional difference between 5MGE and 6MGE blocks if they are different so I can measure the one with the 6M crank and see what it is.