from the CNC milled logos, i'd say its a SPeed Tech build, for "KH" (not sure if its personalization or a model)....it looks like 12 injectors, 2 throttle bodies, 90 degree V6 design, block doesnt look CAST, but It'd have to have been cast first then extensively milled...from aluminum....looks to be all aluminum engine.. (block and heads are aluminum, along with intake system)...heads looks HUGE...far too big to be based on a buick design, theres the appearance it could be overhead cam engine, but it loks like its a pushrod engine from the top bore for a camshaft, OR a balance shaft, and the cavities for what appears to be either water jackets, or pushrods....need more info as well. 560 cubic inches in a 6 cyl design, clearly huge bore and stroke..something in the range of 4.00"-4.50" bore with 4" stroke? (am aware that 3.8L/231s are 3.8" bores on average with a 3.4" stroke...)
ok im not sure, but apparently a bore of 4.64 and stroke of 5.745 v6 got close to 560 cubic inches according to an online calculator...and on another forum, this engine seems to be designed to be twin turbo'd and used for SAND RACING.....as in run as hard up a hill as possible without blowing up the engine and whoever gets to the top wins....dominated by V6s and 4wd SUVs....