Originally posted by drift
yes and no... it's a 2.5 litre. they took an H22A, bored it to 90mm, then used the H23's crank to stroke it (a billet version thereof). the block had a deck plate installed to accomodate a longer rod to help square up the rod/stroke ratio and improve high rpm performance and reduce side forces within the rotational assembly.
the ideal rod/stroke ratio is 1.75:1 the H23 is about 1.59:1 and the H22 is 1.64:1 or something like that. i had everything written in a build log somewhere, but have had no success with finding them since i moved. 
actually i believe the h22 is 1.58, not positive though...and also I dont believe its possible to have an H23 that is better than an H22, just think of the advantages of having 2 different sets of cams? i mean its ideal....they dont really make a whole of cams in the form of turbo cams for the h22, but if you really know what you're doing a made a custom turbo cam for the h22, it would be unreal