what modifications of hs 142f exist? the trade names ive heard of are audew, jdmspeed, cdh, flying horse ect. are they manufactured according to the same documentation with the same dimensions and tolerances of parts, irrespective of factory, year or every factory makes its own changes? engines of different brands have slightly different outside design. would 142f audew parts be interchangeable with cdh power, jdm speed? ive heard that some have straight/tapered shaft, keyed/v mount, how many standards are there? can i put chain transmission on an engine that had t belt and vise versa?